AU2013263732A1 - Irrigation system - Google Patents

Abstract

A travelling irrigator (1) including a primary fluid distribution outlet (12) in the form of a rotating boom (10) configured to rotate around an axis (9), and a secondary fluid distribution outlet (1 5) in the form of a sprayer (1 4 ) positioned in close proximity to the boom axis (9), and a pressurised fluid source (5) connected to the boom (10) and sprayer (14), characterised in that the travelling irrigator (1 ) is configured such that in use the sprayer (14) distributes fluid supplied by the pressurised fluid source (5) to a further distance from the axis (9) than fluid is distributed from the boom (10).

Description

IRRIGATION SYSTEM TECHNICAL FIELD This invention relates to an irrigation system and in particular a travelling irrigator system. 5 BACKGROUND ART Travelling irrigators are used widely in the agricultural industry. New Zealand in particular has a history of using these irrigators to distribute a large quantity of fluid such as water and effluent over many thousands of acres. 0 Because of the distance and volumes required, a reliable means of a reliable irrigator design was needed that worked continuously and could travel over vast amounts of less than perfect terrain without requiring significant intervention or maintenance from the farmer. To address this need, travelling irrigators were developed such as that described in New Zealand Patent No. 210739/210791. These irrigators work by having pressurised fluid pushed 5 through a rotatable spray boom connected to a wheeled frame. Fluid exiting the end of the boom causes the boom to rotate around and drive a winch which engages an anchored cable to pull the irrigator in a linear fashion. This general principle of operation has been very successful and reliable, and has also been employed in a number of other irrigators, such as those described in New Zealand Patent No. 514549, New Zealand Patent No. 578084, New 20 Zealand Patent No. 504997 and New Zealand Patent No. 515951. However, there are universal problems plaguing irrigators. A major issue is fluid application rate which is a function of application depth and soil infiltration rate. For the efficient application of fluid, the irrigator needs to travel at a speed that ensures that there is sufficient coverage in terms of area, along with sufficient depth to which the fluid travels 25 - generally to the extent of the roots of the crop being irrigated. This can take considerable fine tuning and optimal irrigation is rarely achieved. For example, different soil types absorb the fluids at different rates. Therefore, if the application rate is too great, the soil is unable to absorb the fluid and run-off can occur. This can lead to a significant environmental hazard, particularly so, if the fluid being applied is effluent. 1 A high application rate can lead to leaching leading to poor nutrient retention in the paddocks as well as nitrification of nearby streams and waterways. However, if there is a low application rate, insufficient fluid will be absorbed by the soil causing aridification of the land and most likely crop failure. 5 Another problem is that if the application rate is within a desired range, it can be that the irrigator is travelling too slowly to efficiently cover all of the land that requires irrigation. This can lead to some of the land being adequately irrigated whereas the rest of the land may not be attended to in time, or the farmer will have to buy multiple irrigator systems. As can be appreciated, none of these situations are desirable. 0 All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this 5 reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country. Throughout this specification, the word "comprise", or variations thereof such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, .0 or group of elements, integers or steps. It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice. Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only. 25 DISCLOSURE OF THE INVENTION According to one aspect of the present invention there is provided a travelling irrigator including a primary fluid distribution outlet in the form of a rotating boom configured to rotate around an axis, and 30 a secondary fluid distribution outlet in the form of a sprayer positioned in close proximity to the 2 boom axis, and a pressurised fluid source connected to the boom and sprayer, characterised in that the travelling irrigator is configured such that in use the sprayer distributes fluid supplied by the 5 pressurised fluid source to a further distance from the axis than fluid is distributed from the boom. According to another aspect there is provided a method of distributing fluid from a travelling irrigator having a primary fluid distribution outlet in the form of a rotating boom configured to rotate around an 0 axis, and a secondary fluid distribution outlet in the form of a sprayer positioned in close proximity to the boom axis, and a pressurised fluid source connected to the boom and sprayer, characterised by the step of 5 distributing fluid from the sprayer to a further distance from the axis than fluid from the boom. It should be appreciated that the present invention solves a number of the problems associated with the prior art. The provision of two separate fluid outlets fed from a pressurised fluid source means that the application rate distributed from the boom is less than that of previous irrigator designs. This means that the soil can better absorb the fluid without runoff or leaching. 20 The second aspect of the applicant's invention is to ensure a greater area is covered by having the more centrally disposed sprayer throw out fluid to a greater area than that covered by the boom. Thus, in combination the boom and the sprayer cover a greater area than previous irrigators, apply fluid at a rate that can be absorbed to the right extent by the soil and as a consequence of the greater area and slower travel are at least as efficient as previous 25 irrigators. Reference throughout the specification shall now be made to the fluid being distributed as being effluent. It should be appreciated however that this is given by way of example only and the fluid may be water, milk or any other liquid which may or may not have some solids contained therein. 3 In preferred embodiments of the present invention it is envisaged that the rotating boom may be of a similar construction to that used in other irrigators, for example the applicant's Green Back Spider Team irrigator. While this does not preclude improvements to existing booms, it is 5 recognised that current designs work well and are reliable. Therefore, a typical boom for use with the present invention consists of an arm which extends from the irrigator frame having a nozzle at one end and a connection to a drive mechanism at the other. Also connected to the boom is a pressurised irrigation supply (preferably effluent) that pushes fluid (and maybe solids) through the irrigator frame and into the hollow boom so o that fluid emerges from the nozzle at the end thereof. In a preferred embodiment, the secondary fluid outlet (or sprayer) is positioned along with axis about which the boom rotates, this is not essential as in some embodiments the gun could positioned separately to the boom axis of rotation. For example, the definition of the term "close proximity' could be used to describe the 5 positioning of the sprayer onto a sled or trailer attached to the irrigator. For example the sprayer may be coupled to inlet of the irrigator and the irrigator flow could be adjusted to ensure the rate of travel. This embodiment would only require the sprayer to irrigate 270 which will cover both sides and behind the irrigator. You can see that this embodiment could allow the present invention to .0 either be incorporated into the new machine or added to a prior art machine as discussed in the background art. An alternative embodiment exemplifying the term "close proximity' is positioning the sprayer to the front frame of the irrigator. This will require the inlet to have a T joint in it so that liquid can be sent to the rotating boom or to the sprayer fixed to the irrigator frame. 25 If the boom is positioned on the axis of rotation, as in preferred embodiments, it is a relatively easy matter for it to share the pressurised fluid supply directly without necessitating a complicated manifold. The sprayer may come in a number of forms. For example this may be an impact/gear drive liquid sprinkler. 30 In preferred embodiment, the sprayer is in the form of a rain gun such as that sold under that trade mark SIME SYNKROTM. 4 Rain guns can handle dairy effluent and water irrigation and operate by rotating around a fixed shaft to distribute fluid over a wide area. This is contrast to a traditional boom which have the entire boom arm rotating. 5 In some embodiments there may be more than one secondary fluid outlet. For example, there may be two rain guns fitted to the centre point of the irrigator and configured to fire on opposing sides of the irrigator (left/right) as it travels along the paddock. It should be appreciated that in order to have both the gun and boom attached to the same fluid supply and the boom to be able to rotate while the gun is on a fixed shaft requires a o considerable amount of engineering design to implement. Therefore, one embodiment of the present invention the irrigator includes a gland sealing spindle that allows the boom to rotate while the gun and shafts remain static plus ensuring that there is no or minimal leakage around the spindle. The gland system uses oil seals which rotate and seal around a spindle in the form of a 5 stainless steel tube. Three of these seals fit together either side of the fluid. Tests have proven this to be a very reliable way of sealing. In preferred embodiments the irrigator has two booms extending out of the irrigator frame and opposite to each other. Both booms are preferably fitted with nozzles and distribute fluid at approximately the same rate as each other, thus providing balance to the irrigator. .0 However, in some embodiments there may only be one boom and nozzle extending out from the irrigator frame. However in order to balance the irrigator, there may be provided another arm and/or counterweight which could spin around the irrigator axis. The irrigator could still balance and perform without a counter weight but this would cause increased pressure on the bearings and seals in the cam/gland assembly. 25 It should be appreciated that care needs to be taken to ensure that the ratio of fluid passing through the boom and the gun along with the coverage of each outlet needs to be carefully planned to ensure uniformed distribution. On high risk soils the absorption rates vary between 10mm and 20mm per hour. In a preferred embodiment the present invention operates with around 300 kPa of pressure. 30 This pressure has been chosen to suit the preferred boom rotation speed with a 13mm diameter nozzle. 5 With this set up a gun nozzle is matched to the flowrate of the gun. For example when the flowrate is say around 5 litres per second then a 14mm diameter nozzle will be fitted to the gun to maintain the 300kPa of pressure. The inventor has found that a ratio of one third of fluid flow passing through the boom to two 5 thirds through the gun works particularly well. This is because a standard boom irrigator with a standard pressurised fluid supply has a throw of approximately 10 meters radius. That same fluid supply divided between the boom and gun provides a 25 to 40 meter radius from the gun. The radius varies depending on flowrate, and in one version when the flowrate is at 5 litres per second the radius will be 25 m and when the flowrate is 9 litres per second the radius will be o around 40 m. It can be seen that the present invention has a number of advantages over the prior art. Firstly, there is provided a travelling irrigator that can apply fluid at application rates that can be readily absorbed by the soil and provide coverage at a rate that remains efficient. Reduced labour input is a significant advantage for the farmer as with the double the spread 5 width, the irrigator can travel at half the travel speed up the paddock, which effectively cuts the labour input by half. Further, with the irrigator running large nozzles (13mm and up) the irrigator/gun can apply raw effluent at a low rate and sufficient depths. BRIEF DESCRIPTION OF DRAWINGS .0 Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which: Figure 1 is a diagrammatic partial view of a travelling irrigator in accordance with one embodiment of the present invention, and 25 Figure 2 is an exploded view of a gland packed spindle in accordance with one embodiment of the present invention. BEST MODES FOR CARRYING OUT THE INVENTION With respect to Figure 1 there is provided a partial view of a travelling irrigator generally 30 indicated by arrow (1). 6 The irrigator (1) includes a frame (2) which supports a number of the componentry making up the irrigator (1). The frame (2) consist of a number of hollow pieces of metal tubing welded together to provide a 5 robust structural frame work. The frame (2) includes an axle (3) connected to wheels (4). The bottom centre of the frame (2) is connected to a conduit (5) which in turn is connected to a pressurised fluid supply (not shown). The frame (2) also holds a cable drive mechanism generally indicated by arrow (6) of which is o positioned approximately centrally with respect to the frame (2). Extending out from the frame (2) to the opposite side of the fluid inlet (5) is a connecting structure (not clearly shown) enabling the irrigator to be connected to a tractor, quad bike or the like. A cable (8) extends out from the cable assembly (6) in the direction of the connector assembly (7) so that in use it can be attached to a structure such as a fence and act as an anchor point 5 for the irrigator (1). Connected to the fluid inlet (5) is a central axis generally indicated by arrow (9). Two boom arms (10) are rotatably connected to the axis (9) by a gland packed spindle (11). The arrangement of the axis (9), the gland packed spindle (11) and boom arm (10) is such that fluid entering the irrigator (1) via the inlet (5) passes through the axis (9) and along the boom .0 arm (10) to emerge from the nozzle (12). The pressure of the water exiting from the nozzle (12) causes the boom arm (10) to spin around the axis (9). As the axis (9) is connected to a drive mechanism (not clearly shown) associated with the cable mechanism (6), its rotating action causes the cable mechanism (6) to wind in the cable (8) pulling the irrigator towards its anchor point (not shown). 25 Extending from the gland packed spindle (11) is a fixed centre shaft (13) to which a sprayer (generally indicated by arrow 14) is fixed. In this embodiment, the sprayer is a SIME

SYNKRO

T M rain gun. The rain gun (14) moves around the central axis (9), and is likewise powered by pressurised fluid coming in from the inlet (5). Alternative positioning of the rain gun (not shown) can be on a sled of trailer coupled to the inlet 30 of the irrigator and trailed behind it. Another place that the gun could be positioned is on the front frame of the irrigator with 7 appropriate plumbing around the inlet to enable the fluid to go the boom of the gun. In operation, the nozzle (12) of the boom (10) is approximately a third of the size of the nozzle (15) of the gun (14). This means that under typical pressurised flow rates of 5 litres per second to 12 litres per second, the boom (10) throws effluent to a radius of approximately 10 meters, 5 whereas the gun (14) throws effluent to a distance of approximately 25 to 40 meters. This combination of distribution ensures that there is relatively even coverage of fluid relative to the ground and at a rate that can be readily absorbed by the soil. It should be appreciated that flow rates can change with nozzle sizing on the gun. As the flow rate coming from the boom (10) is less than traditional, the irrigator (1) travels o slower. However, the greater throw provided by the gun (14) means that a greater area is covered and lower application depths can be applied due to the wider area the effluent is being applied to. An important component of the irrigator (1) is the gland packed spindle (11), illustrated in exploded form in Figure 2. 5 The spindle (11) includes a lower manifold (24) with a centre shaft (19) connected to the fluid supply (not shown) via inlet (20). Inlet (20 is connected to inlet (5). The shaft (19) has apertures (21) which align with conduits (22) in the upper manifold (23) that connect to the boom arms (10). The lower manifold (24) also contains part f the cable mechanism (6). 0 The outlet (25) of the upper manifold (23) connects to the centre shaft (13). Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope of the appended claims. 8

Claims (18)

1. A travelling irrigator including a primary fluid distribution outlet in the form of a rotating boom configured to rotate around an axis, and 5 a secondary fluid distribution outlet in the form of a sprayer positioned in close proximity to the boom axis, and a pressurised fluid source connected to the boom and sprayer, characterised in that the travelling irrigator is configured such that in use the sprayer distributes fluid supplied 0 by the pressurised fluid source to a further distance from the axis than fluid is distributed from the boom.

2. A travelling irrigator as claimed in claim 1 wherein the boom includes an arm which extends from the irrigator frame having a nozzle at one end thereof and a connection to a drive mechanism at the other end thereof. 15

3. A travelling irrigator as claimed in claim 2 wherein the boom is connected to a pressurised irrigation supply that pushes fluid through the irrigator frame and into the boom so that fluid emerges from the nozzle at the end thereof.

4. A travelling irrigator as claimed in any one of claims 1 to 3 wherein the secondary fluid outlet is positioned along the axis around which the boom rotates. 20

5. A travelling irrigator as claimed in any one of claims 1 to 4 wherein the secondary fluid outlet is coupled to the inlet of the irrigator.

6. A travelling irrigator as claimed in any one of claims 1 to 4 wherein the sprayer is 9 positioned on the front of the irrigator frame.

7. A travelling irrigator as claimed in any one of claims 1 to 6 wherein the secondary fluid outlet is in the form of an impact/gear drive liquid sprinkler

8. A travelling irrigator as claimed in any one of claims 1 to 6 wherein the secondary fluid 5 outlet is in the form of a rain gun.

9. A travelling irrigator as claimed in any one of claims 1 to 8 which includes a gland sealing spindle that allows the boom to rotate while the secondary fluid outlet and associated shafts remain static.

10. A travelling irrigator as claimed in any one of claims 1 to 9 which includes two booms 0 extending out of the irrigator frame and opposing each other.

11. A method of distributing fluid from a travelling irrigator having a primary fluid distribution outlet in the form of a rotating boom configured to rotate around an axis, and a secondary fluid distribution outlet in the form of a sprayer positioned in close proximity 5 to the boom axis, and a pressurised fluid source connected to the boom and sprayer, characterised by the step of distributing fluid from the sprayer to a further distance from the axis than fluid from the boom. 20

12. A method as claimed in claim 11 wherein the fluid is effluent.

13. A method as claimed in either claim 11 or claim 12 where the irrigator flow is adjusted to ensure the rate of travel. 10

14. A method as claimed in any one of claims 11 to 13 wherein the irrigator is operated at around 300kPa of pressure with a boom having a 13mm diameter nozzle.

15. A method as claimed in claim 14 wherein the irrigator is operated to have a flow rate of around 5 litres/second and the secondary fluid outlet has a 14mm diameter nozzle. 5

16. A method as claimed in any one of claims 11 to 15 which is operated to have an approximate ratio of one third of fluid to flow passing through the boom to two thirds of the fluid flow passing through the secondary fluid outlet.

17. A travelling irrigator substantially as herein described with reference to the accompanying figures and examples in the Best Modes Section. 0

18. A method of distributing fluid from a travelling irrigator substantially as herein described with reference to the accompanying figures and examples in the Best Modes Section. Williams Engineering 2011 Limited by its Attorneys JAMES & WELLS INTELLECTUAL PROPERTY 11