GB2214239A

GB2214239A - Apparatus for harnessing power from natural fluid flows

Info

Publication number: GB2214239A
Application number: GB8901129A
Authority: GB
Inventors: Robert Lewis Morgan
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-01-25
Filing date: 1989-01-19
Publication date: 1989-08-31
Also published as: GB8901129D0

Abstract

An apparatus for harnessing power from a fluid flow such a river comprises at least two cylinders 2, 2' having parallel axes and disposed apart and athwart the current flowing in the river. The apparatus also includes a continuous belt 4, encircling the cylinders having at least one vane 6, rotatable about an axis perpendicular to the direction of the fluid flow, means for positioning each vane obliquely with respect to the current and means, coupled to at least one cylinder, for transmitting power from the fluid flow through rotation of the cylinder. The apparatus is relatively simple, robust, easy to maintain and can be fabricated from easily available local materials. Details are disclosed of means for mounting the or each vane on the belt (Fig 3) and for pivoting the or each vane. Details are also disclosed of a hydraulic accumulator supplied by means of a piston driven by the fluid flow driven apparatus by means of a crank (Fig 5). <IMAGE>

Description

APPARATUS FOR HARNESSING POWER FROM A FLUID FLOW The present application relates to an apparatus for harnessing power from a fluid flow and particularly, but not exclusively, to an apparatus for harnessing power from a river or stream.

In many undeveloped areas of the world there are often unused water power sources. The usual method of harnessing power from the water resource is by installation of a dam. Installation of such a dam is limited by the number of sites along a river where the construction of the dam is both feasible and worthwhile. Large dams are typically complex and expensive. Furthermore large dams may involve the flooding of areas of productive agricultural land and in some regions, dams have proved self defeating, in that the reservoirs silt up and lose their holding capacity.

Also the power generated by hydro-electric dams is usually far more than is needed locally and so has to be distributed over a large area through an expensive system of powerlines and transformer stations.

The present invention aims to provide an apparatus for harnessing power from a fluid flow such as a river, without resorting to a dam and obviating the aforementioned difficulties.

According to the present invention there is provided an apparatus for harnessing power from a fluid flow comprising at least two cylinders, each cylinder having parallel axes and disposed apart and athwart a direction of fluid flow, a continuous belt encircling the cylinders, the belt having at least one vane rotateable about an axis perpendicular to the direction of fluid flow, means for positioning the or each vane obliquely with respect to the direction of fluid flow, and means coupled to at least one cylinder, for transmitting power from the fluid flow through rotation of the cylinder.

This apparatus is relatively simple, robust, easy to maintain and can be fabricated from easily available local materials.

Embodiments of the present invention are defined in the accompanying claims 2 to 13.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a schematic cross section of a preferred embodiment of the present invention; Figure 2 is a schematic cross section along the line AA of figure 1; Figure 3 is an enlargement of a vane such as shown within the box B marked in figure 2; Figure 4 is a schematic cross section of a cylinder and part of a belt according to a second preferred embodiment; and Figure 5 is a schematic diagram of a means for storing power according to a third preferred embodiment of the present invention.

The preferred embodiment of the apparatus comprises two cylinders, 2, 2' which are disposed athwart a direction of fluid flow, such as one placed on each bank of a river. The cylinders 2,2' are aligned having parallel ages, which are perpendicular to the direction of fluid flow. A continuous belt 4 encircles each cylinder 2,2'. The belt 4 comprises an upper portion 4' and a lower portion 4" fabricated from a suitable flexible material and coupled between them are a plurality of vanes 6, of which only a few are shown on the left hand side, These upper and lower belts 4', 4" are relatively narrow and the upper one 4' may be so situated in the river so as to permit water vessels to pass over.

Each vane is rotateable about an axis perpendicular to the direction of fluid flow. Each vane is coupled to the belt 4 by way of a pair of sandwiching plates 8.

One plate 8 provides an axis point 10 for enabling the vane 6 to rotate thereabout. Furthermore each plate 8 provides arms 12 having stops 14 for enabling each vane 6 to be held obliquely with respect to the direction of fluid flow. Each vane 6 is capable of swiveling on its bearings as it emerges from the cyclinders 2,2' on the downstream side and so maintain their drive. The apparatus may also include other means for reversing the attitude of the vanes 6 as each one passes round a cylinder. Also each stop 14 may include a rubber or similar cushioning pad to prevent the vane 6 from jarring each time the vane 6 flips over.

Alternatively the plates 8 may dispense with the arms 12 and stops 14 and provide light cables attached to the belt 4 and vane 6 for positioning each vane 6 obliquely with respect to the direction of fluid flow.

When the apparatus is positioned athwart a fluid flow such as a river the current acting on each of the vanes 6 enable the belt 4 to be forced into motion and accordingly rotate each of the cylinders 2, 2'. Either both or one axis from the cylinders 2, 2' may be coupled to a means for transmitting the power through rotation of the cylinder. In Figure 1, cylinder 2 is coupled to such means, which comprises a rotating shaft 16 driven by the cylinder 2 through a bevel gearing (not shown).

Any means for transmitting the power may be used such as a gearing or other machinery and the power may be transmitted directly where required or to an accumulator.

The apparatus may be fixed to the river bed by a number of ways. In figure 1 the axis of cylinder 2 is embedded in a bearing within a concrete block, which in turn is embedded in the river bed. Cylinder 2' is not embedded in the river bed, but its axis is held by a framework sliding in holes in post 18, which is embeddded in the river bed.

Alternatively the cylinders 2, 2' need not be fixed to the river bed, but the cylinders 2, 2' may be weighted from below, whilst having a small positive buoyancy so that the cyclinder 2, 2' float having the upper part of the belt 4' below the surface of the river. Lines or other means attached to the river bed and to the cylinders, 2, 2' enable the apparatus to maintain its position. Also the cylinders 2, 2' may be kept at an optimium distance apart and the belt 4 being kept taut by a rod or girder (not shown) between the cylinders 2, 2'.

A combination of the above ways of fixing the apparatus to the river bed may be used, for example attaching one end to the bank providing a pivot whilst the other end is attached to a float and maintained in position by a cable attached to the other river bank at a point further upstream. If the river is wide, then intermediate points may be established by coupling a line from the river bank upstream to the intermediate points. Furthermore, a floating outer end or intermediary points may be coupled to lines which are attached to anchors on the river bed upstream. Also idler wheels may be introduced having vertical axles between the upstream and downstream belt.

In some instances the width of the river may be so large that the tension on the belt would be so great as to lead to a high probability of breakage. This may be overcome by dividing the apparatus into a number of separate sections each having a separate belt. The cylinders at each end of adjacent belts are coupled by gearings, such as a horizontal shaft with bevel gears at each end meshing with both gears at the top of the cylinders or by a chain and running over spocket wheels In order to provide optimum efficiency of the apparatus, the belt must be maintained taut and each vane should be maintained in the vertical position. Accordingly a line 20 working over pulleys to a winch on the bank, with a brake or ratchet, may be used to keep the belt for taut.Furthermore a line 22 may be run from cylinder 2 to 2 to facilitate keeping the vanes 6 in the vertical position.

Alternatively, the belts 6 may be kept taut by being fabricated from ropes or by chains, in which each link has the pivot of one vane 6 fitted therein.

The second preferred embodiment shown in figure 4 comprises a cylinder 2 having recesses 24 for coupling with each of the axis points 10 of the vanes 6. This enables the belt 4 not to transmit power to the cylinders 2 by friction, but by positively locking the axes 10.

A third preferred embodiment of the present invention is described in figure 5. The apparatus may include means for accumulating power from the fluid flow through the rotation of the cylinder. A crank is attached to an axis of one of the cylinders 2 and through a connecting rod, this rod reciprocates with a piston and body of water (not shown) which in turn reciprocates with a piston 26 in a cylinder 28 via a pipe 79. In turn this piston 26 drives piston 30 in a smaller cylinder 32.

Through non return valves 34, 36 this draws water from the river and forces it into a long, normally vertical, cylinder 38. The cylinder 38 may be provided with a heavy piston 40 or a ram carrying a weighted apparatus.

Alternatively the weight may be provided by a tall column of water, in which case this cylinder 38 would normally need stay wires to the surrounding ground. The cylinder 38 acts as a power accumulator and quantities of water at high pressure may be drawn off intermittently to operate a machine such as a hydraulic press when the weighted piston 40 descends a certain distance. At other times the piston 40 is being steadily raised by the pumping in of new water into the cylinder 38.

A pipe 44 may be used to drive low pressure machinery.

A further pipe 46 may be provided as a safety outlet.

The aforegoing description has been given by way of example only, and it will be appreciated by persons skilled in the art that modifications may be made without departing from the scope of the present invention.

Claims

1. An apparatus for harnessing power from a fluid flow comprising at least two cylinders each cylinder having parallel axes and disposed apart and athwart a direction of fluid flow, a continuous belt encircling the cylinders, the belt having at least one vane rotateable about an axes perpendicular to the direction of fluid flow, means for positioning the or each vane obliquely with respect to the direction of fluid flow, and means coupled to at least one cylinder, for transmitting power from the fluid flow through rotation of the cylinder.

2. An apparatus as claimed in claim 1, further comprising means for accumulating power.

3. A claim as claimed in claim 2, in which the means for accumulating power comprises an hydraulic accumulator.

4. A claim as claimed in any one of claims 1 to 3, in which the means for positioning the or each vane obliquely with respect to the direction of fluid flow comprises a line coupled to the belt and coupled to the extremity of the or each vane.

5. Apparatus as claimed in any one of the preceeding claims, in which the means for transmitting power comprises a rotating shaft coupled to a bevel gearing, the bevel gearing being coupled to at least one cylinder.

6. Apparatus as claimed in any one of claims 1 to 4, in which the means for transmitting power comprises a first cylinder housing a first piston, the first piston being coupled to a second piston, the second piston being housed in a second cyclinder, and the second cylinder having an inlet and outlet pipe each having a non return valve.

7. Apparatus as claimed in any one of the preceeding claims, further comprising means for maintaining the belt taut.

8. Apparatus as claimed in any one of the preceeding claims. in which each cylinder includes at least one recess for engaging with the or each vane.

9. Apparatus as claimed in any one of the preceeding claims, in which the fluid flow comprises a river.

10. Apparatus as claimed in claim 9, in which at least one cylinder is embedded in a river bank.

114 An apparatus as claimed in claim 9 or claim 10 in which at least one cylinder is provided with a weight, a positive buoyancy and a line coupled to the river bank for positioning the cylinder.

12. An apparatus as claimed in any one of the preceeding claims. comprising four or more cylinders, and at least two belts, each belt encircling two cylinders for forming a chain having adjacent cylinders coupled together.

13. Apparatus substantially as hereinbefore described with reference to any one of figures 1 to 5.