WO2012063263A2

WO2012063263A2 - Balloon assisted tilt up tower

Info

Publication number: WO2012063263A2
Application number: PCT/IN2011/000772
Authority: WO
Inventors: V. Rajagopal Raghunathan
Original assignee: Raghunathan V Rajagopal
Priority date: 2010-11-11
Filing date: 2011-11-11
Publication date: 2012-05-18
Also published as: WO2012063263A3

Abstract

According to an aspect of the present invention, there is provided a system for tilting up the tower for minimizing the stresses experienced due to gravity on a inclined tower structure during installation. The present invention as shown in Fig.(1) comprises of lighter than air balloon anchored operably to tower by means of single or multiple steel wires. By increasing the quantity of the lighter-than- air gas in the balloon, buoyancy forces reduces the load acting downwards due to self-weight of the tower and the wind turbine or any instrument is minimized. By bringing down the amount of gas (Hydrogen or helium) or temperature (in case of hot air) inside the balloon close to atmospheric air and also by operating the anchor by means of anchor wires, the lighter than air balloon tends to descend thereby the tower can be tilted down for repair and maintenance purpose.

Description

Title of Invention

Balloon Assisted Tilt up Tower

Field of the Invention

This invention relates to the tilt up tower with unique methodology of lifting it by means of lighter than air balloon. The current method of the tilt up tower requires the design to withstand the stress developing on the tower while erecting it or tilting it down. So, it requires sturdier design of tower thereby it is more expensive. When the tower is tilted by means of winches through guy wires excessive stress are developed on the structures which may cause the tower to collapse. The present invention of erecting the tilt up tower along with wind turbine or any communication instrument utilizes the buoyant force of the lighter than air balloon to neutralize or reduce the stresses developed on the tower which paves the way to design the tower for stand up mode thereby the tower can be built and erected at lower cost than the existing systems.

Background and prior art of the Invention

With the wind industry developing at rapid phase, companies involved in this sector are coming up with new designs day by day with the capacity of generating enormous amount of power. Also the rotor and tower size increases with the outcome of new designs. Installing a wind turbine or any communication instrument at the top of a tower can be both difficult and expensive; therefore a tilt-up tower is often preferred. In a tilt-up tower the base of the tower is fitted to a hinge which is bolted into the concrete foundations and often a gin pole is also fitted to the base of the tower which acts as a mechanical arm to give leverage to raise the tower.

With such a system, the top of the tower can be tilted down to ground level for installation of the wind turbine or any communication instrument for future maintenance. The whole structure can then be man hauled or winched up to the vertical relatively painlessly and safely. At least two and more if possible people should be on hand to help erect the wind turbine or any communication instrument keeping the guy wires taught and the ascent smooth. A tilt-up tower must have guy wires on four sides (rather than the usual three) because it is impossible to safely tilt up a tower with guy wires on just three sides. After assembly of the tower, wind turbine or any communication instrument, and tower wiring on the ground, the tower and turbine or any communication instrument are tilted-up to the vertical position using a winch (optional) or a vehicle. A winch is preferred because of the greater control they afford. The towers are provided with a lever arm, called a gin-pole, which runs from the base to one of the guy anchors. The gin-pole converts the pulling force on the pull-up rope or cable into a lifting force on the turbine or any communication instrument and tower.

Although the tilt up tower is preferred over mono pole tower, in order that the tower should with stand the stresses developing while tilting it up or down, it is always designed for tilt up mode. Even though the main objective of the tower relies on with standing the load by heavy winds it is designed for the maximum stresses developed at the tower while erecting it or tilting it down. So, it leads to sturdy design with more material thickness and thereby the material and manufacturing cost is higher.

A few patents are typical of the known prior art attempting to improve the methods of erecting the tilt up tower. For example, U.S Pat. No. 4408958 to Alen.P.Hinderson discloses a tall tilt up tower capable of supporting a heavy wind turbine generator that starts out as multiple independent tubular sections which are nested inside each other while in a generally horizontal position. The above invention minimizes the need of the need of extra heavy lift cranes while erecting or tilting down the tower.

While U.S Pat. No: 2010/0083604 to Bent Vangsy discloses a lattice tower comprising of first section, composed of a first part and a second part, and a second section pivotally connected along an axis, the lower part of the tower being composed by the second section, that includes the legs of the lattice tower and the first part of the first section and the upper part of the lattice tower being composed by the second part of the first section. The above invention uses simple trolleys to erect the tower rather than erecting it by large cranes.

But none of the prior art documents disclose a method of erecting the tilt up tower at low erecting and manufacturing cost and also relieving or minimizing the stresses developing on the tower while it is tilted up or down.

Summary of the Invention According to aspect of the present invention, there is provided a system for erection of tilt up tower with the aid of lighter than air balloon for its cost effective and reliable erection. The steel wires from the balloon are anchored to the tilt up tower. Also, guy wires from the ground are anchored to various points of the tower for reducing the stress points while the tower is erected or it is tilted down. The guy wires anchored to the tower keep the stresses on the tower to a minimum. The gin pole attached at right angle to the tower increase the leverage while the tower is being tilted up or down. The buoyant force on the balloon compensates the gravitational pull due to the self weight of the tower and the turbine or any communication instrument mounted on it which eliminates the bending stresses on the tilt up tower while erecting it. The bending stresses are neutralized or minimized by lighter than air balloon and guy wires thereby providing the way for the safe and economical erection of tower. The balloon is anchored to adjust its position manually or through auto controls accordingly while erecting or tilting down the tower.

Object of the Invention

It is an object of the Invention lu provide a cost effective and reliable method of erection of till up tower of the wind turbine or any other tower structures, monopole or lattice towers.

It is an object of the invention to design a tilt up tower for stand up mode which will reduce the material cost

It is an object of the invention to provide a method of erecting the tilt up tower with elimination or minimizing the bending stresses developing on the tower structure.

It is an object of the invention to provide a lighter than air balloon to assist in tilting up and tilting down the tower by means of buoyancy force acting upon it.

It is yet another object of invention to compensate the gravitational pull due to the self weight of the tower and the wind turbine or any communication instrument by means of buoyant force.

It is yet another object of the invention to tilt down the tower for repair and maintenance by means of lighter than air balloon assisted by guy wires. Statement of the Invention

The erection of tilt up tower with the assistance of lighter than air balloon comprising of

A. The lighter than air balloon (1) anchored to the tilt up tower by means of single or multiple steel wire for tilting up or down the tower.

B. The steel wire (2) connecting the lighter than air balloon with the tilt up tower.

C. The tilt up tower (3) pivoted at its one end by means of base plate and the other end housing the turbine or any communication instrument.

D. The wind turbine (4) or any communication instrument installed on the top of the tower.

E. Guy wires (5) anchored at various stress points of the tower for the tower to withstand very high winds and keep the stresses on the tower to a minimum.

F. The gin pole (6) attached to right angles to the tower (ground position) increase the leverage while the tower is being tilted up or down.

G. The base plate (7) through which the tilt up tower is pivoted for tilting it up or down.

H. The winch (8) for exerting mechanical pull or to with hold the gravitational pull on the tower and the wind turbine or any communication instrument by means of guy wire.

I. The anchor (9) for adjusting the position of lighter than air balloon accordingly while erecting or tilting down the tower.

J. The anchor wires (10) to have control over the position of lighter than air balloon while the tower is being tilted up or down.

While erecting the tilt up tower, the self weight of the tower and the turbine or any communication instrument develops enormous bending stresses which will cause the tower to deform and collapse and also since it is designed for tilt up mode, the structure is sturdy with more material thickness is more to withstand the stresses developed in the tower. The present invention relieves or minimizes the stresses by means of buoyancy force acting upon the lighter than air balloon and also it is can be designed for stand up mode thereby reducing the material cost and it paves the way for ease of erection at reasonable cost.

Tilt up mode Design: 2011/000772

The tilt up tower is subjected to maximum stresses while erecting it or tilting it down than it is at upright position. In order that the tower should withstand the stress, the present traditional towers are designed considering the stresses developing at erecting or tilting it down which is said to be tilt up mode design. So, it leads to sturdy design with more material thickness thereby the material and manufacturing cost is high.

Standup mode Design:

The present invention employs the method of designing the tilt up tower only by considering the stresses that will develop in the tower while it is in upright position by means of the heavy winds or by centrifugal force of the components mounted over it thereby it eliminates the need of sturdy design thereby the tower can be built and erected at low cost. So, the present invention allows us to design the tower at low material and manufacturing cost which is said to be stand up mode design.

Lighter than air Balloon:

The present invention utilizes buoyancy force to tilt up or down the tower by means of lighter than air balloon. The lighter than air balloon uses gases having low density than air and by varying the quantity of the gases occupying the balloon, it can be made to ascend or descend which will also tilt up or tilt down the tower respectively. Any gas having low density than air like hot air, Neon, Ammonia, Hydrogen, Helium and methane can be utilized to have buoyancy effect.

Buoyancy:

Buoyancy is an upward acting force, caused by fluid pressure that opposes an object's weight. If the object is either less dense than the liquid or is shaped appropriately, the force can keep the object afloat. In the present invention, the lighter than air gas or hot air in the balloon is less dense than surrounding air which makes the balloon to float and lift the tower anchored to it. This phenomenon is utilized here for the economic and reliable erection of tilt up tower.

Working conditions: The present invention of erection of tilt up tower comprises of two modes of operation

A. Tilt up condition

B. Tilt down condition(only in the case of repair and maintenance) Tilt up condition:

As shown in Fig2, 2(a), by varying the lighter than air gas or the temperature of hot air(in case of hot air balloon) in the balloon, the buoyancy effect on it is increased since the density of the lighter than air gas or hot air occupying the balloon is low than the surrounding air. So, the balloon tends to rise by buoyancy principle which eventually lifts or tilts up the tower anchored to the balloon by means of single or multiple steel wires.

Tilt down condition:

When there is a need to tilt down the tower for repair or maintenance, the balloon is raised or made to float to the corresponding height of the tower and then steel wire from the balloon is anchored to the tower. Then by operating the anchor, the balloon is brought down by means of anchor wires which eventually tilt down the tower to the desired height. Also, the position and relative movement of balloon can be adjusted by means of anchor.

The method of tilting up the tower by means of assistance from lighter than air balloon comprises of:

A. The inflated lighter than air balloon (1) is anchored to the tilt up tower by means of single or multiple steel wires (2).

B. The guy wires (5) are anchored at various stress points of the tower to minimize the stress on the tower (3) while erecting or tilting it down.

C. The quantity of lighter than air gas or hot air which is lighter than air occupying the balloon (1) is increased which induces buoyancy effect on the lighter than air balloon (1).

D. The balloon (1) tends to float by the buoyancy force acting upon it.

E. The rising balloon (1) assists in tilting up the tower (3) while the guy wires (5) provide support to the tower (3). F. The lighter than air gas or hot air occupying the balloon (1) is increased till the tower (3) attains the upright position.

G. The guy wires (5) are anchored to the ground at a distance from the structure's base to add stability to structures.

The method of tilting down (in case of repair and maintenance) the tower by means of assistance from lighter than air balloon and guy wires comprises of:

A. The inflated lighter than air balloon (1) is raised to height of the tower (3) by feeding lighter than air gas inside the balloon (1).

B. The balloon (1) is anchored to the tower by means of single or multiple steel wires (2).

C. The balloon (1) is brought down by operating the anchor (9) by means of anchor wires (10).

D. The position of the balloon (1) relative to the tower (3) is adjusted accordingly by means of anchor (9).

E. The tower (3) anchored to the balloon (1) is tilted down with the assistance of the lighter than air balloon (1) which is pulled down by means of anchor(9) or by varying the supply of lighter than air gas or hot air inside the lighter than air balloon(1).

F. The tower (3) is brought down to the desired height for maintenance or repair.

Brief Description of the Drawings

Fig.1 illustrates the tilt up tower at ground condition with the lighter than air balloon anchored to the tower by means of steel wires.

Fig.2, 2(a) illustrates the tilt up tower being lifted by lighter than air balloon by means of buoyant force.

Fig.3 illustrates the tilt up tower is tilted upright up with the assistance of lighter than air balloon and support of guy wires respectively.

Fig.4 illustrates a block diagram showing the steps involved in tilting up the tower with the aid of lighter than air balloon. Fig.5 illustrates a block diagram showing the steps involved in tilting down the tower with the aid of lighter than air balloon.

Detailed Description of the Drawings

The other and further features, advantages, and benefits of the invention will become apparent in the following description taken in conjunction with the following drawings. It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory but are not to be restrictive of the invention. The accompanying drawings which are incorporated in and constitute a part of this invention, illustrate one of the embodiments of the invention, and together with the description, serve to explain the principles of the invention in general terms. Like numerals refer to like parts throughout the disclosure. It was with knowledge of the foregoing state of the technology that the present invention has been conceived and is now reduced to practice.

Fig.1 illustrates the tilt up tower at ground condition with the lighter than air balloon anchored to the tower by means of steel wires. Before lifting the tower (3), guy wires (5) are anchored to the tower for minimizing the stress imposed upon the tower (3). The lighter than air balloon (1) is inflated by blowing the lighter than air gas or hot air (in case of hot air balloon) to get its optimal shape and it is anchored to the tower (3) by means of single or multiple steel wires (2). Also, guy wires (5) from the tower (3) are anchored to some mechanical means to exert some force at the gin pole (6) to tilt up or down the tower (3)·

Fig.2, 2(a) illustrates the tilt up tower being lifted by lighter than air balloon by means of buoyant force. On feeding the lighter than air gas or hot air inside the balloon (1) the density of the lighter than air gas or hot air inside the balloon (1) becomes lower than surrounding air. So, according to the buoyancy principle the balloon (1) floats while the tower (3) is being lifted along with it. So, by feeding more quantity of lighter than air gas or hot air the balloon (1) tends to go up further and also it assists in lifting up to 20- 50% of total load by means of buoyancy force which opposes the gravitational pull due to self weight of the tower (3) and the turbine (4) or any communication instrument mounted on it. While tilting up the tower(3) with the wind turbine(4) or any communication instrument mounted over it, enormous stresses develops at various nods of the tower(3) due to self weight of the tower(3) and the turbine(4) or any communication instrument. The stresses developed may even collapse the tower (3) if it exceeds its ultimate strength. In the present invention the buoyancy force acting upon the balloon(1) imposes equivalent and opposite force against the pull of gravity so that the stresses are neutralized or minimized which ensures cost effective and reliable erection and tilt down of tilt up tower(3).

Fig.3 illustrates the tilt up tower is tilted upright up with the assistance of lighter than air balloon and support of guy wires respectively. The tilt up tower (3) with the assistance of lighter than air balloon (1) and pull exerted by mechanical means is tilted to upright position. In order that the tower(3) should withstand against very heavy winds and to be stable, guy wires(5) whose one end is attached to various ends of the tower(3) is anchored to the ground with their other ends at a distance from the structure's base which allows the tension of each guy wire(5) to offset the others.

Fig.4 illustrates a block diagram showing the steps involved in tilting up the tower with the aid of lighter than air balloon.

The method of tilting up the tower by means of assistance from lighter than air balloon and guy wires comprises of:

A. The inflated lighter than air balloon (1) is anchored to the tilt up tower (3) by means of single or multiple steel wires (2).

B. The guy wires (5) are anchored to the various stress points of the tower (3) to minimize the stress on the tower (3) while erecting or tilting it down.

D. The balloon (1) tends to float by the buoyancy force acting upon it.

E. The rising balloon (1) assists in tilting up the tower (3) while the guy wires (5) provide support to the tower (3).

F. The quantity of lighter than air gas or hot air occupying the balloon (1) is increased till the tower (3) attains the upright position. G. The guy wires (5) are anchored to the ground at a distance from the structure's base to add stability to structures.

Fig.5 illustrates a block diagram showing the steps involved in tilting down the tower with the aid of lighter than balloon.

B. The balloon (1) is anchored to the tower (3) by means of single or multiple steel wires (2).

E. The tower (3) anchored to the balloon (1) is tilted down with the assistance of the lighter than air balloon (1) which is pulled down by means of anchor(9) or by bringing the varying the supply of lighter than air gas or hot air inside the lighter than air balloon(1).

The operation of tilting up and tilting down the tower with the turbine or any communication instrument installed at the top is as follows:

While tilting up the tower(3) by mechanical means, enormous stresses are developed at various nods of the structure of the tower(3) due to the load or self weight of the tower(3) and the turbine(4) or any communication instrument together pulled by gravitational force. The stresses are high enough that they may go beyond the ultimate stress thereby causing the tower (3) to collapse. In this invention the vertical load acting downwards is neutralized or minimized by equivalent and opposite buoyant force acting on the lighter than air balloon (1). By increasing the quantity of lighter than air gas or the temperature of hot air occupying the lighter than air balloon(1), it tends to float due to the buoyancy forces acting upon it which also lift the tower(3)anchored to the balloon(1) by means of single or multiple steel wires(2). By increasing the quantity of the lighter than air gas or hot air inside the balloon (1), it rises further since the density inside the balloon (1) is less than that of surrounding air. The tower(3)is tilted up with the assistance from the buoyancy force of lighter than air balloon(1) and support from the guy wires(5) for its stability and to minimize the stress. As soon as the tower(3) is tilted to upright position the guys wires(5) whose one end anchored to the tower(3) is anchored to the ground at their other ends for the tower(3) to with stand against the heavy winds. The position and the movement of the balloon (1) are controlled by anchor (9) by means of anchor wires (10).

While tilting down the tower(3) in case of repair and maintenance, the balloon(1) is raised to the height of the tower(3) by buoyancy force acting on the balloon(1) as explained earlier. It is then anchored to the tower (3) and the balloon(1) is brought down by operating the anchor(9) by means of anchor wires(10) either manually or through auto controls and thereby the tower(3) is tilted down along with the balloon(1).

It will be obvious to a person skilled in the art that with the advance of technology, the basic idea of the invention can be implemented in a plurality of ways. The invention and its embodiments are thus not restricted to the above examples but may vary within the scope of the claims.

Further the above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.

Reference Listings:

1. LIGHTER THAN AIR BALLON

2. STEEL WIRE

3. TILT UP TOWER

4. WIND TURBINE

5. GUY WIRES

6. GIN POLE

7. BASE PLATE

8. WINCH

9. ANCHOR

10. ANCHOR WIRES

Claims

CLAIMS:

1. The erection system of tilt up tower with the assistance of lighter than air balloon comprising of:

D. The wind turbine (4) or any other communication instrument installed on the top of the tower.

E. Guy wires (5) are anchored to the tower for the tower to enhance the strength and stiffness of the tower.

F. The gin pole (6) attached to right angles to the tower (ground position) to increase the leverage during tilt up or down the tower.

H. The winch (8) for exerting mechanical pull or to with hold the gravitational pull on the tower and wind turbine or any communication instrument by means of guy wire.

2. The system as claimed in claim 1 wherein the lighter than air balloon (1) is anchored operably to the tower (3) and the wind turbine (4) or any communication instrument by means of single or multiple steel wires (2).

3. The system as claimed in claim 1 wherein the tower(3) can be tilted up or down with its end pivoted at the base plate(7).

4. The system as claimed in claim 1 wherein the wind turbine (4) or any communication instrument is mounted on top of tower (3).

5. The system as claimed in claim 1 wherein the guy wires(5) anchored to the tower(3) at various nodes is anchored to the ground at their other ends for structural stability of the tower(3) against heavy winds.

6. The system as claimed in claim 1 wherein the winch(8) or other mechanical means for exerting pull and to withhold the tower(3) while tilting it up or down by means of guy wires(5).

7. The system as claimed in claim 2 wherein the lighter than air balloon (1) ascends or descends by law of floating or buoyancy principle.

8. The system as claimed in claim 7 wherein the quantity or temperature(in case of hot air) of the lighter than air gas or hot air occupying the lighter than air balloon(1) is raised or lowered by varying the input depending upon the need of tilting it up or down.

9. The system as claimed in claim 8 wherein the load acting downwards due to the self weight of the tower(3) and the wind turbine(4) or any communication instrument is overcome or neutralized by buoyancy force acting upwards on the lighter than air balloon(1).

10. The system as claimed in claim 9 wherein the breaking stresses acting on the tower(3) is relieved or minimized by means of buoyancy force on the lighter than air balloon(1 ).

11. The system as claimed in claim 10 wherein the tower (3) is designed only for stand up mode which significantly reduces the material cost, manufacturing cost and weight.

12. The method of tilting up the tower as claimed in claim 1 by means of assistance from lighter than air balloon and guy wires comprises of:

A. Anchoring the Inflated lighter than air balloon (1 ) to the tilt up tower (3) by means of single or multiple steel wires (2)

B. Anchoring the guy wires (5) to various stress points of the tower (3) to minimize the stress on the tower (3) while erecting or tilting it down

C. Increasing the quantity of the lighter-than-air gas or the temperature of hot air which is lighter than air occupying the balloon which induces buoyancy effect on the lighter than air balloon (1) D. Causing the balloon (1) to float by the buoyancy force acting upon it.

E. Tilting up the tower (3) by means of the rising balloon while the guy wires (5) provide support to the tower (3)

F. Increasing the quantity of lighter than gas or hot air occupying the balloon till the tower attains the upright position

G. Anchoring the guy wires (5) to the ground at a distance from the structure's base to add stability to structures

13. The method of tilting down (in case of repair and maintenance) the tower as claimed in claim 1 by means of assistance from lighter than air balloon and guy wires comprises of:

A. Raising the Inflated lighter than air balloon (1 ) to height of the tower (3) by feeding lighter than air gas inside the balloon (1)

B. Anchoring the balloon (1 ) to the tower (3) by means of single or multiple steel wires (2)

C. Bringing down the balloon (1 ) by operating the anchor (9) by means of anchor wires (10).

D. Adjusting the position of the balloon (1) relative to the tower (3) accordingly by means of anchor (9)

E. Tilting down the tower (3) anchored to the balloon (1) by the pull exerted on the lighter than air balloon which is pulled down by means of anchor (9) or by varying the supply of lighter than air gas or hot air inside the lighter than air balloon(1)

F. Bringing down the tower (3) to the desired height for maintenance or repair

14. The system as claimed in claim 1 wherein the erection of tilt up tower(3) with the assistance from lighter than air balloon(1) also implies to the other microwave structures, high voltage transmission tower and other structures involving the need.

15. The system as claimed in claim 1 wherein the tilting up or down the tower with assistance from lighter than air balloon and method substantially as herein described with respect to the accompanying drawings.