WO2009100476A1

WO2009100476A1 - Pivot irrigator drive system

Info

Publication number: WO2009100476A1
Application number: PCT/AU2008/000179
Authority: WO
Inventors: Todd James Simmons
Original assignee: Vinidex Pty Limited
Priority date: 2008-02-14
Filing date: 2008-02-14
Publication date: 2009-08-20
Also published as: AU2008350784A1

Abstract

A pivot irrigator drive system, including generation (64) of electrical power from a flow of irrigation water through an axial flow turbine assembly (38). Also disclosed is a self-driven pivot irrigator (10), the irrigator (10) comprising a) a boom (16) rotatable about a central pivot (12); b) a spray mechanism associated with the boom (16) for distribution of water from the boom (16) as the boom (16) rotates about the central pivot (12); and c) a turbine (38) located between a water inlet and the spray mechanism, whereby water us ducted from the inlet to the spray mechanism, at least a portion of the water ducted through the turbine (38), the turbine (38) driving a generator or alternator (64) which produces electrical power for controlled driving of one or more electric motors (81) which cause the boom (16) to rotate while water is ducted from the inlet to the spray mechanism.

Description

PIVOT IRRIGATOR DRIVE SYSTEM

The present invention relates to pivot irrigators and, more particularly, to electrically driven pivot irrigators.

BACKGROUND

Irrigators for coverage of areas of cultivation typically comprise of a span for a water conducting manifold feeding multiple water spray nozzles along the length of the boom, The boom is generally supported on a number of driven, wheeled struts.

A central pivot irrigator includes a central tower (the pivot) about which the boom rotates, driven by one or more wheeled struts disposed at least at the outer end of the boom and at one or more intermediate locations depending on the size of the system. The wheels of the struts may be driven hydraulically or electrically. Water is pumped from dam or other surface sources, or from artesian bores and supplied to the irrigator under pressure serving the dual purpose of providing water for irrigation and the energy for the hydraulic or electrical drive system.

Known electrically driven irrigators rely on a remote power electrical power source, either from an expensive to install and maintain generator or mains power, and require expensive underground cable installation. It is an object of the present invention to address the above disadvantages, or at least provide a useful alternative. Notes

1. The term "comprising" (and ^' grammatical variations thereof) is used in this specification in the inclusive sense of "having" or "including", and not in the exclusive sense of "consisting only of".

2. The above discussion of the prior art in the Background of the invention, is not an admission that any information discussed therein is citable prior art or part of the common general knowledge of persons skilled in the art in any country.

BRIEF DESCRIPTION OF INVENTION

Accordingly, in a first broad form of the invention, there is provided a self-driven pivot irrigator; said irrigator comprising:

(a) a boom rotatable about a central pivot;

(b) a spray mechanism associated with the boom for distribution of water from the boom as the boom is caused to rotate about said central pivot;

(c) a turbine located between a water inlet and said spray mechanism whereby water is ducted from said inlet to said spray mechani'sm; at least a portion of water so-ducted passing through said turbine; said turbine, in use, driving a generator or alternator which produces electrical power for controlled driving of one or more electric motors which cause said boom to rotate whilst water is ducted from said inlet to said spray mechanism.

Accordingly, in a further broad form of the invention, there is provided a pivot irrigator drive system? said system including generation of electrical power from a flow of irrigation water through an axial flow turbine assembly.

Preferably, said turbine assembly includes a diffuser adapted to change flows of water entering said assembly from substantially parallel flow from a supply pipe to angled flow; said angled flow directing said flows of water to impact blades of a turbine of -said assembly at angles substantially normal to surfaces of said blades.

Preferably, water flow impacting on said axial flow turbine is controlled by a water diverter system; said water diverter system including a diverter pipe extending from said supply pipe- to a delivery pipe so as to bypass said turbine assembly.

Preferably, said diverter system includes a manual or solenoid operated flow control valve mounted in said diverter pipe.

Preferably, said axial flow turbine assembly is mounted in an extended end. section of a pipe tee junction; said extended end section coupled to said delivery pipe.

Preferably, said diffuser includes a central drum with vanes disposed about said drum; each of said vanes defining a section of a helical flow path wherein water flow entering said diffuser is changed from said substantially parallel flow in said supply pipe to said angled flow; said angled flow substantially normal to angled surfaces of blades of said axial flow turbine.

Preferably, a drive shaft coupled^' to said turbine is supported in a drive shaft housing; said drive shaft housing mounted in an opposite end section of said pipe tee junction.

Preferably, said drive shaft is coupled to a generator or alternator; said generator of alternator mounted to said- drive shaft housing.

Preferably, said system includes a control module. -^■ o "

Preferably, said control module includes a programmable logic controller.

Preferably, said control module controls power supplied to driving wheels of said span.

Preferably, said control module controls charging of a battery bank of said system.

Preferably, said control module controls said solenoid . operated flow control valve.

Preferably, said control module regulates speed of rotation of said span relative to available water delivery and generated electrical power,

In another broad form of the invention, there is provided a method of driving into rotation a span . of a pivot irrigator; said method including the steps of:

(a) providing water under pressure to a supply pipe of a drive system of said irrigator,

(b) diverting a proportion of said water through a diversion pipe and flow control valve,

(c) directing a proportion of said water through a turbine assembly,

(d) coupling a generator or alternator to a turbine of said turbine assembly, (e) providing electrical power generated by said generator or said alternator to electric motors of drive wheels o£ support struts of said span.

Preferably, water flow impacting on blades of said turbine is substantially normal to surfaces of said blades.

Preferably, said turbine assembly includes a diffussr; said diffuser comprising a central drum and vanes; said vanes defining helical water flow paths wherein flows. of said water entering said turbine assembly are changed in direction from flows substantially parallel to said supply pipe_r to flows normal to angle surfaces of said turbine blades.

Preferably, a control module controls proportions of water directed through said turbine assembly and through said diversion pipe and said control valve.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the present invention will now be described with reference to the accompanying drawings wherein:

Figure 1 is a perspective view of a pivot irrigator in which electrical power is generated from irrigation water passing through a turbine according to a preferred embodiment of the invention,

Figure 2 is a sectioned view of a pivot irrigator power generating system according to a preferred embodiment of the invention^

Figure 3 is a schematic representation of the main electrical components of the pivot irrigator of a preferred embodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The drive system of the present invention is an electrical drive system, with power generated from water flowing to the irrigator under pressure..

Figure 1 shows a typical pivot irrigator installation 10 to which the present drive system of the invention is applied. Installation 10 includes a fixed central support structure 12 mounted to a base 14.

Support structure 12 supports a rotating span 16 pivotally mounted to the upper collar 18 of support structure 12, Span 16 comprises a water carrying manifold spine 20 forming part of a fabricated cage structure providing one or more spans 22. A first span extends between fixed support structure 12 and a first wheeled strut 24, with additional spans extending between subsequent wheeled struts. The wheels 26 of each of the wheeled struts 24 are driven by electric motors (see Figure 3) under control of a programmable logic controller 82 in control module 28 mounted at the fixed central support structure 12.

With reference also now to Figure 2, water is supplied to the drive system 30 through a large bore supply pipe 32. A smaller bore diversion pipe 34 fitted with a manual or solenoid operated flow control valve 36 provides a means of controlling the flow of water entering an axial flow 'turbine assembly 38 interposed in the main water flow path from supply to irrigator span 16. Turbine assembly 38 is mounted within an extended end section 40 of a tee junction 42, downstream from the diversion pipe take-off junction 44.

Water, once past the turbine assembly 38 is driven up into the outlet section 46 of tee junction 42 and into a large bore delivery pipe 48. Water from the diversion pipe 34 also enters the delivery pipe 48. From here water is directed via central feed pipe 50 to the distribution manifold spine 20 of the span via a swivel connector 52.

Mounted in the opposite end section 54 of tee junction 42 from the turbine assembly 38, is a drive shaft housing 56 supporting drive shaft 62 connected to turbine 74. Housing 56 is provided with end seals and bearings 58 with the output end 60 of drive shaft 62 coupled to an alternator or generator 64.

The efficiency of the present system lies in the efficiency of energy extraction from the flow of water of turbine assembly 38. As can be seen in Figure 2, the assembly 38 includes a diffuser 66 at the water entry point of the assembly. Diffuser 66 comprises a central drum 68 with a number of vanes 70 arranged around the drum, with the vanes shaped so as to direct flows of water passing through the diffuser 66 from the initially parallel flow through large bore pipe 32_r into flows impacting the angled blades 72 of turbine 74.

In effect, water flowing through diffuser 66 follows a helical path directed by the vanes 70 curving part-way around drum 68, The blades 72 of turbine 74 are so shaped that water impacts the blades at an angle substantially normal to the blade surface, thus extracting the maximum kinetic energy from the water mass.

Power provided by the generator or alternator 64 is fed to the drive wheel motors of the wheeled struts 24 thus causing the span 16 to rotate about central fixed structure 12. Control module 28 controls the power supplied to the individual drive wheels 26 of the span 16. In addition, control module 28 provides for charging of battery bank 80 so that sufficient power is available to move the span 16 when not irrigating (for example to move out of the way of other working equipment) .

The precise tailoring of the diffuser 66 and turbine blade 72 design provides for a significant reduction in the pressure flow of water required by the system, sufficient to provide the electrical power needed to drive the irrigator .

The arrangement of the present invention in which irrigation water is used to generate the power required to drive the irrigator into rotation avoids the need for expensive underground cabling and the installation and maintenance of a remote generator set, and hence provides a significant saving in operating costs.

The above describes only some embodiments of the present invention and modifications, obvious to those skilled in the art, can be made thereto without departing from the scope of the present invention.

Claims

1. A pivot irrigator drive system; said system including generation of electrical power from a flow of irrigation water through an axial flow turbine assembly.

2. The drive system of claim 1 wherein said turbine assembly including a diffuser adapted to change flows of water entering said assembly from substantially parallel flow from a supply pipe to angled flow; said angled fiow directing said flows of water to impact blades of a turbine of said assembly at angles substantially normal to surfaces of said blades.

3. The drive system of claim 2 wherein water flow impacting on said axial flow turbine is controlled by a water diverter system; said water diverter system including a diverter pipe extending from said supply pipe to a delivery pipe so as to bypass said turbine assembly.

4. The system of claim 3 wherein said diverter system includes a manual or solenoid operated flow control valve mounted in said diverter pipe.

5. The system of any one of claims 2 to 4 wherein said axial flow turbine assembly is mounted in an extended end section of a pipe tee junction; said extended end section coupled to said delivery pipe.

6. The system of any one of claims 2 to 5 wherein said diffuser includes a central drum with vanes disposed about said drum; each of said vanes defining a section of a helical flow path wherein water flow entering said diffuser is changed from said substantially parallel flow in said supply pipe to said angled flow; said angled flow substantially normal to angled surfaces of blades of said axial flow turbine.

7. The system of claim 5 or 6 wherein a drive shaft coupled to said turbine is supported in a drive shaft housing; said drive shaft housing mounted in an opposite end section of said pipe tee junction,

8. The system of claim 7 wherein said drive shaft is coupled to a generator or alternator; said generator or alternator mounted to said drive shaft housing.

9. The system of any one of claims 1 to 8 said system including a control module.

10. The system of claim 9 wherein said' control module includes a programmable logic controller.

11. The system of claim 9 or 10 wherein said control module controls power supplied to driving wheels of said span.

12. The system of any one of claims 9 to 11 wherein said control module controls charging of a battery bank of said system.

13. The system of any one of claims 9 to 12 wherein said control module controls said solenoid operated flow control valve.

14. The system of any one of claims 9 to 13 wherein said control module regulates speed of rotation of said span relative to available water delivery and generated electrical power.

15. A method of driving into rotation a span of a pivot irrigator; said method including the steps of:

(b) diverting a first proportion of said water through a diversion pipe and flow control valve,

(σ) directing a second proportion of said water through a turbine assembly, (d) coupling a generator or alternator to a turbine of said turbine assembly,

(e) providing electrical power generated by said generator or said alternator to electric motors, thereby to cause said span to pivot whilst at the same time utilising at least a proportion of said water for irrigation directed from said span.

16. The method of claim 15 wherein water flow impacting on blades of said turbine is substantially normal to surfaces of said blades.

17. The method of claim 15 or 16 wherein said turbine assembly includes a diffuser; said diffuser comprising a central drum and vanes; said vanes defining helical water flow paths wherein flows of said water entering said turbine assembly are changed in direction from flows substantially parallel to said supply pipe, to flows normal to angle surfaces of said turbine blades.

18. The method of any one of claims 15 to 17 wherein a control module controls proportions of water directed through said turbine assembly and through said diversion pipe and said control valve.

19. The method of any one of claim? 15 to 18 wherein said electric motors drive wheels of support struts of said span.

20. A self-driven pivot irrigator; said irrigator comprising;

{a) a boom rotatable about a central pivot;

(σ) a turbine located between a water inlet and said spray mechanism whereby water is ducted from said inlet to said spray mechanism;

at least a portion of water so-ducted passing through said turbine; said turbine,, in use, driving a generator or alternator which produces electrical power for controlled driving of one or more electric motors which cause said boom to rotate whilst water is ducted from said inlet to said spray mechanism.