GB2286228A

GB2286228A - Fluid powered generator

Info

Publication number: GB2286228A
Application number: GB9402222A
Authority: GB
Inventors: Malcolm Alan Williams
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-02-05
Filing date: 1994-02-05
Publication date: 1995-08-09
Anticipated expiration: 2014-02-05
Also published as: GB9402222D0; GB2286228B

Abstract

A fluid powered electricity generator 20 comprises a housing 22 defining inlets 24a - 24d and an outlet 26. A rotor 28 is rotatably mounted in the housing 22 and defines radially extending blades 30 spaced around the circumference of the rotor, the housing inlets 24a - 24d being arranged such that the flow of fluid approaching the rotor 28 is substantially tangential thereto. An energy convertor, such as a dynamo (34, Fig. 3), is linked to the rotor 28 for converting the rotational energy of the rotor into electricity. The generator (20) may be placed in a stream or river in conjunction with a dam, weir or intake chute (12, Fig. 1) or may be mounted in the keel or rudder of a boat. <IMAGE>

Description

FLUID POWERED GENERATOR This application relates to a fluid powered electricity generator.

In developing countries, or in remote sites, there is frequently no ready access to an electricity supply.

Small petrol or diesel powered generators may be utilised though these require a supply of fuel which must be transported to the site and, particularly in developing countries, such fuel may be prohibitively expensive for the users. Solar panels may be utilised, however these are very expensive and, with current technology, only produce a relatively small amount of electricity. Wind turbines may be utilised but, again, only provide a small amount of electricity. Hydro-electricity is perhaps the least expensive form of electricity but, with conventional arrangements, involves substantial capital outlays in the building of dams and the provision of turbines and the like, and is not suited for temporary or small scale applications.

It is among the objects of the invention to provide a water powered electricity generator which may be manufactured using readily available, low cost materials and which can be installed or re-sited with minimal capital expense.

According to the present invention there is provided a fluid powered electricity generator comprising: a housing defining an inlet and an outlet; a rotor rotatably mounted in the housing and defining radially extending blades spaced around the circumference thereof, the inlet being arranged such that the flow of fluid approaching the rotor is substantially tangential thereto; and energy conversion means linked to the rotor for converting the rotational energy of the rotor into electricity.

Preferably, the inlet defines a plurality of inlet portions for directing fluid, typically water, in separate streams, onto spaced portions of the rotor circumference.

Most preferably, the cross-sectional area of each inlet portion reduces towards the rotor, to provide a venturi effect.

Preferably also, the rotor defines tangential surface portions adjacent each blade, for directing water onto the blades.

Preferably also, the energy conversion means is driven through contact with a circumferentially extending surface portion of the rotor. Most preferably, the energy conversion means is in the form of one or more dynamos, alternators or other mechanical electromagnetic energy producing devices.

In use, the generator may be provided in conjunction with a weir, dam or the like to provide a head of water to drive the rotor. To minimise water depth and space requirements it is advantageous to arrange the generator such that the axis of rotation of the rotor is substantially vertical. For certain applications, the generator may be provided in combination with a flexible sheet that may be configured and anchored in a stream of water to form a weir having a floor portion and including an opening at a lower portion of the weir for communication with the generator inlet. Such an arrangement may further include means for permitting water flow through the generator only when a certain head of water is available, such as a float linked to a pivoting door.

Alternatively, the generator may be provided in combination with a duct or chute for location in a stream of water and for directing water through the generator, preferably increasing the velocity of the water as it passes through the chute. Such a chute may be utilised, for example, in an area of water subject to tidal currents. In such an application it is desirable that the generator and chute may pivot to take advantage of both directions of tidal flow.

In a further aspect of the invention the housing may be mounted below the waterline on the hull of a waterborne craft, for example the housing may form part of the keel of a yacht such that the movement of the yacht through water, or the anchoring of the yacht in a tidal current, will result in the generation of electricity for use on board the yacht. Also, a generator mounted in the steering rudder may obviate the need for an engine driven alternator, which is otherwise a constant drain on the propelling engine shaft power, resulting in improved engine fuel consumption.

The generator may be provided in conjunction with other energy conversion arrangements, such as wind turbines, solar panels and the like.

The generator may provide electricity for a water heater forming part of a water filtration and purification system. Such a system may also include an electrically driven pump.

This and other aspects of the present invention will now be described, by way of example, with reference to accompanying drawings, in which: Figure 1 is a perspective view of a water powered electricity generating system in accordance with one embodiment of the present invention; Figure 2 is a sectional plan view of the generator of the system of Figure 1; Figure 3 is a sectional side view of part of the generator of Figure 2; Figures 4, 5 and 6 are side, front and plan views of a water powered electricity generator system in accordance with a further embodiment of the present invention; Figures 7, 8 and 9 are side, front and plan views of a water filtration system incorporating a water powered electricity generator in accordance with a still further embodiment of the present invention; and Figure 10 is a sectional view of the filter arrangement of the system of Figure 7.

Reference is first made to Figure 1 of the drawings which illustrates a water powered electricity generating system 10 in accordance with one embodiment of the present invention. The system 10 is adapted for location in a stream or river in which the water flows in the direction of arrow A. A rectangular tarpaulin has been folded and secured with ropes to define a floored weir, 12 the edges of which are secured to the bank or river bed by fixing rings 14, 15 and ropes 16, 17. An opening 18 is provided in the lower downstream portion of the weir 12 and communicates with the inlet of a water powered generator 20.

The generator 20 includes a shallow rectangular housing 22 and a sectional plan view of the housing 22 is shown in Figure 2 of the drawings. The housing 22 defines inlets 24a, b, c, d, and an outlet 26. A rotor 28 is mounted within the housing between the inlets and the outlet and defines a plurality of radially extending blades 30. The inlets 24 are spaced along the front face of the housing 22 and each reduces in cross-section to provide a venturi. The inlets 24 are arranged such that the water is flowing tangentially to the rotor 28 as it flows into the rotor cavity and thus impinges on the blades 30 substantially at right angles to the blade surfaces. To assist in producing this effect the rotor 28 defines tangential surface portions 32 adjacent each blade surface.

The rotor 28 is mounted in the housing 22 on a pair of fully floating multibearing axles. Thus, each axle may withstand up to 50% seizure without seriously impeding rotation.

Energy conversion means are linked to the rotor 28 for converting the rotational energy of the rotor into electricity. In this embodiment a plurality of bicycle dynamos, one of which is shown in Figure 3 of the drawings are located within a waterproof housing 44 (Figure 1) provided on the upper surface of the housing 22. Each dynamo 34 is mounted on the top wall of the housing 22 with the dynamo body 38 located above the wall 36 while the dynamo driving wheel 39 is located within the housing 22 in contact with a driving disc 40 mounted on the top of the rotor 28. The dynamo 34 is mounted on an adjustable base plate 42 which is bolted to the wall 36.

The output from the dynamos 34 may be utilised directly or to charge a battery from which power may be drawn as required.

The load on the rotor 28, which depends on the number of dynamos 34 fitted, determines the head of water which will be sufficient to turn the rotor 28 and thus generate electricity. To control the flow of water to the rotor 28 a door may be provided for the opening 18, the door being linked to a float arrangement such that the door will only open when the water behind the weir 12 reaches a predetermined level. Also, the opening 18 may be provided with a protective grid to prevent stones, fish and the like from passing into the generator 20 and possibly damaging or jamming the rotor 28.

Reference is now made to Figures 4, 5 and 6 of the drawings which illustrate a water powered electricity generating system 50 in accordance with a further embodiment of the present invention. The system 50 includes a generator 20 as described above, though the system is intended for location in areas of water subject to tidal currents rather than in a stream or river. A rigid tapering chute 52 is pivotably mounted on a post 54 secured in the sea bed 56. An opening 58 is provided at the narrow end of the chute 52 and communicates with the inlet 24 of the generator 20. A pair of rudders 60 linked by a wing 64 are mounted on the generator housing 22 to assist in aligning the chute 52 in the tidal current.

Reference is now made to Figures 7, 8 and 9 of the drawings which illustrate a gravitational filtered water system 70 in accordance with a still further embodiment of the present invention. The system 70 includes two water tanks 72, 73 separated by a filter arrangement 74. The tanks and filter are located within a housing 76 having water inlets 78, 79 and outlets 80, 81. The inlets 78, 79 are linked to a water supply which provides a sufficient head to move the water through the filters 74, as will be described, and also to power a generator 20 provided in the lower section of the housing 76. Electricity output from the generator 20 charges a pair of batteries 82 provided within the housing 76, which operate thermostat controlled immersion heaters (not shown) in the second tank 73.

As mentioned above, the head of water is sufficient to transfer water from the first tank 72 through the filter 74 and into the second tank 73, from which heated and filtered water may be obtained from the outlet 80.

The filter arrangement 74 is illustrated in greater detail in Figure 10 of the drawings and comprises four stages 84, 85, 86, 87. The first stage 84 comprises layers of coarse, medium and fine medium cell foam enclosed within a muslin wrapping. The second stage 85 comprises muslin enclosed activated carbon, while the third stage comprises a fine porous ceramic core. A PVC grill 88 held in place by a reducer 90 retains the first three stages in a filter tube 91, water passing through the grill 88 into a drop tube 92. From the drop tube 92 the water passes through a smaller diameter tube 94 onto a drip controlled spray fan 94 in a second filter tube 95 before passing into the fourth stage 87 which comprises filter wool and hexnodes.

After passing through the hexnodes the water passes into the second tank 73.

In alternative embodiments the water may be pumped through the filter 74 by means of a pump powered from the batteries 82. In addition, the electricity produced by the generator 20 may be supplemented by wind-turbines mounted on the housing 76 and by solar panels suitably mounted on the housing 76.

From the description of these embodiments it will be clear to those of skill in the art that the present invention provides a very simple means for generating electricity, and is particularly suitable for use in remote or less developed areas. The major parts of the systems may be manufactured from readily available and inexpensive materials, for example the generator housing and rotor may be formed of marine plywood. In addition, the generator 20 may be used in conjunction with a very simple weir or chute arrangement and does not require the time consuming and expensive construction of dams and the like. Thus, the generator may be installed or re-sited relatively easily. Further, in smaller sizes, the generator is portable, and a number of generators may be operated together where the water supply permits.

It will further be evident to those of skill in the art that the above described embodiments are merely exemplary of the present invention and that various modifications and improvements may be made thereto without departing from the scope of the present invention.

Claims

1. A fluid powered electricity generator comprising: a housing defining an inlet and outlet; a rotor rotatably mounted in the housing and defining radially extending blades spaced around the circumference thereof, the inlet being arranged such that the flow of fluid approaching the rotor is substantially tangential thereto; and energy conversion means linked to the rotor for converting the rotational energy of the rotor into electricity.

2. The generator of claim 1 wherein the inlet defines a plurality of inlet portions for directing fluid, in separate streams, onto spaced portions of the rotor circumference.

3. The generator of claim 2 wherein the cross-sectional area of each inlet portion reduces towards the rotor, to produce a venturi effect.

4. The generator of any one of claims 1, 2, or 3, wherein the rotor defines tangential surface portions adjacent to each blade, for directing water onto the blades.

5. The generator of any one of the preceding claims wherein the energy conversion means is driven through contact with a circumferentially extending surface portion of the rotor.

6. The generator of claim 5 wherein the energy conversion means is in the form of one or more mechanical electro-magnetic energy producing devices.

7. The generator of any one of the preceding claims in combination with means for providing a head of water to drive the rotor.

8. The generator of claim 7 in combination with a flexible sheet adapted to be configured and anchored in a stream of water to form a weir having a floor portion and including an opening at a lower portion of the weir for communication with the generator inlet.

9. The generator and flexible sheet of claim 8 further including means for permitting water flow through the generator only when a certain head of water is available.

10. The generator of any one of claims 1 through 6 wherein the generator is provided in combination with a duct or chute for location in a stream of water and for directing water through the generator.

11. The generator and duct or chute of claim 10 in which the duct or chute and the generator are pivotally mountable in a fluid stream.

12. The generator of any one of the preceding claims in combination with a further energy conversion arrangement.

13. The generator of any one of the preceding claims in which the generator forms part of a water filtration and purification system.

14. The generator of any one of claims 1 through 6 wherein the housing is adapted for mounting below the water line on the hull of a water borne craft.

15. The fluid powered generator substantially as described herein and as illustrated in Figures 1, 2 and 3, or Figures 4, 5 and 6, or Figures 7, 8 9 and 10 of the accompanying drawings.