NZ554193A

NZ554193A - Vehicle mounted fertiliser processing and spreading

Info

Publication number: NZ554193A
Application number: NZ55419307A
Authority: NZ
Inventors: Brett Ashley Emeny
Original assignee: Brett Ashley Emeny
Priority date: 2007-03-27
Filing date: 2007-03-27
Publication date: 2008-09-26

Abstract

A vehicle (2) mounted dispersion system (1) is disclosed. The dispersion system (1) includes a storage compartment (3) for particulate material, a fluid storage tank (4), and an applicator (5) configured to disperse a fine particle suspension. The dispersion system (1) also includes a processor (7) configured to receive coarse particulate material from the storage compartment (3) and to process the coarse particulate material to form a fine particulate material. The fine particulate material is mixed with fluid from the fluid storage (4) tank to produce a fine particle suspension for dispersion by the applicator (5).

Description

<div class="application article clearfix" id="description"> 10055361561* fntellectuai ProP<my Office of M 7 PATENTS FORM NO. 5 Fee No. 4: $250.00 PATENTS ACT 1953 COMPLETE SPECIFICATION After Provisional No: 554193 Dated: 27 March 2007 DISPERSION SYSTEM I Brett Ashley Emeny, a New Zealand citizen, of 102 Norfolk Road, Inglewood, New Zealand hereby declare the invention for which I pray that a patent may be granted to me, and the method by which it is to be performed to be particularly described in and by the following statement: James & Wells Ref: 127948/62 DISPERSION SYSTEM TECHNICAL FIELD The present invention relates to a system for dispersion of material. In particular the invention relates to a system of processing and application of particulate 5 material. BACKGROUND ART It is well known that the yield of crops and pasture may be increased by the timely application of fertiliser and other soil additives. As well as timing, it is important that fertiliser is applied in the correct amount and distributed over the ground in a 10 way that each plant can achieve full benefit. The constituents of many common fertilisers are manufactured initially in a powdery state. Powders are generally not suited for application from containers (buckets, hoppers etc) as it may be difficult to control the flow of powder from the container. As a consequence most common fertilisers are produced and sold in 15 granulated form, mainly to improve the flow characteristics of the fertiliser, but also to reduce problems with handling powders, as granules show less of a tendency to form a dust, pack down or absorb moisture. A number of dispersion systems have been developed and used extensively to apply granulated fertilisers. Granulated fertiliser may be loaded into a hopper (or 20 bucket) for aerial application, for example by helicopter or fixed wing aircraft. Fertiliser in granulated form may be an advantage for such applications in that, as well as moving freely from the hopper, the weight of the granules reduces drift, thus helping to ensure that the fertiliser falls in the desired location. However, 2 James & Wells Ref: 127948/62 aerial application is generally only practical and cost effective for relatively large areas of land. Land based applications are also common, for example from a truck or trailer, the fertiliser being distributed as the truck or trailer is driven over the area to be 5 fertilised. Specialised vehicles, called spreader trucks, are commonly used to apply granulated fertiliser. A typical spreader truck has a storage chamber, usually in the form of a hopper, into which granulated fertiliser is loaded. The fertiliser may be transferred to an applicator, typically a spinner, by a conveyor belt (or horizontally mounted auger) 10 mounted on the floor of the storage chamber. The applicator and conveyor belt speeds are typically managed by a computerised system so as to control the rate of application and spread width to that appropriate for the speed of the spreader truck. A spinner, which is commonly mounted at the rear of a spreader truck, is a disc 15 that often includes a number of vanes extending radially from the surface of the disc. In use fertiliser (or other material) is dropped onto the rotating disc which propels the fertiliser away from the spinner (and onto the ground). The lateral spread of the distribution of granules is adjusted by varying the speed of rotation of the spinner. 20 One disadvantage of applying granules, either from the air or from a land-based vehicle, is that the resulting distribution of particles is non-uniform, or sporadic, with discrete granules of fertiliser interspersed with regions of no fertiliser. 3 James & Wells Ref: 127948/62 The uptake of fertiliser by the roots of a plant usually occurs as a result of gradual absorption of the fertiliser by water, typically from rainfall or use of an irrigation system. This generally only releases the fertiliser in the near vicinity of the granule. For example, at typical application rates of granulated fertiliser there may around 5 100 granules per square metre, so that the spacing between granules is typically around 10 cm. This may result in an excess of fertiliser in the vicinity of each granule, and a deficit of fertiliser in the region between granules, so that some plants may get more fertiliser than they require, and some little or none. This disparity is likely to lead to 10 a lower yield for the crop or pasture as a whole than could be achieved if each plant received the appropriate amount of fertiliser. One solution to this is to grind the granules into finer particles before distribution. In principle, application of fertiliser in smaller sized particles should result in a more uniform distribution of fertiliser over the ground, and therefore better yield of crop 15 or pasture, for the same amount of fertiliser applied. For example, the same amount of fertiliser as used in the example above applied in the form of fine particles may result in the order of around 1000 particles per square metre. The typical spacing between fine particles may then be around 3 mm. This significantly increases the availability of fertiliser to all plants in the 20 application area and hence should lead to increased yield. However, application of fertiliser as dry fine particulates also has some disadvantages, including the relative ease with which the fine particles may become airborne to form a dust cloud, or may be blown along the ground away from where they were deposited. (Granulated particles are typically too heavy to 4 James & Wells Ref: 127948/62 become airborne under normal circumstances). Once released into the open the dust of fine particles may drift uncontrollably away from the target area to be fertilised. Not only does this constitute a loss in terms of yield, but also may result in fertiliser being deposited in regions where it may in fact be detrimental, for 5 example into waterways. Furthermore, grinding the granules into fine particles is an additional cost during manufacture. The purchase price of fine particles may be several times the costs of the same amount of fertiliser as coarse particles. Another problem is that during storage the fine particles may pack down into a 10 relatively hard block, which must be broken up before application, leading to additional processing and cost. Many fertiliser materials are hydroscopic. Forming such materials into fine particles increases the tendency to absorb moisture, which again may cause problems with packing down and solidification. Absorption of moisture also 15 increases the tendency of the particles to adhere to one another to form larger clumps, and to stick to surfaces. This may result in difficulty with spreading the fertiliser by mechanical means, such as a spinner. The tendency to clump when moistened also defeats the purpose of grinding the fertiliser into fine particles in the first place, as application of the moistened, lumpy material may result in a 20 similar non-uniform distribution to that of granulated fertiliser. In extreme cases, exposure to moisture may result in the fertiliser having to be discarded as it is no longer in a form that can be readily applied. 5 James & Wells Ref: 127948/62 Furthermore, the light weight of fine particles may make them unsuitable for aerial application, or from a vehicle using a spinner (or similar applicator) as the fine particles may readily drift away from the target application area. Some of these problems with fine particles may be overcome by forming an 5 aqueous suspension of the fine particulate matter. Aqueous suspensions of fine particulate matter have been used for many years in aerial dispersion systems, both to provide a uniform spatial coverage of the fertiliser and, as the droplet size of the sprayed suspension is heavier than that of the fine particles, to overcome the problem of drift associated with dry particulate matter. 10 Similar ground based dispersion systems have been used with vehicles fitted with a tank to carry an aqueous fine particle suspension. Such vehicles are commonly fitted with a spray applicator. A disadvantage of using an aqueous suspension is the cost of transporting the suspension from the source to the site of application. The increased cost, in 15 comparison with transporting the dry granular material, arises from the added cost of transporting the water used to form the aqueous suspension. A further disadvantage is that over time the fine particles may settle out of suspension. This may occur, for example, if a batch of fertiliser in a fine particle suspension is loaded into a tank, but only part of the batch is dispersed. If this 20 occurs further stirring and mixing is required in order to restore the fine particle suspension before further application, again leading to additional costs. Fine particle suspensions are generally applied as a spray. However, spraying generally requires greater capital cost in equipment and increased operating costs 6 James & Wells Ref: 127948/62 compared with application of dry material, for example by a spinner. Problems may also arise with blockage of the spray nozzles. As a result of the above problems, it is still common practice to apply granulated fertiliser from a vehicle, such as a spreader truck, particularly for application to 5 small, well defined areas such as paddocks or fields,. However, the amount of dust created during application of dry fertiliser using a spinner remains a problem, even when granular particles are used, as the spinner, which is typically revolving at a high speed, causes some fine particles to be broken off of the granules. These fine particles generally form a cloud of dust 10 which may drift uncontrollably into neighbouring areas. This is a particular problem if the application target area is near a waterway, or near an area of high run off into a waterway. Increasing nitrification of waterways due to application of fertilisers is becoming a major environmental issue in many areas. This may result in more control of fertiliser application, including reducing 15 the amount applied and ensuring that it is contained in the target area. Various modifications to this basic arrangement for a spreader truck have been introduced to address some of the problems described above. For example, US Patent No 3,717,285 (to Hatton), discloses a spray apparatus for a truck including a tank containing water and a mixing bin where coarse particulate 20 fertiliser is combined with water to form a coarse particle slurry that is applied by a spray nozzle. US Patent No 5,267,696 (to Balmer), discloses a truck that is convertible from one mode used to apply agricultural material in liquid form, to another mode used to apply dry material. 7 James & Wells Ref: 127948/62 US Patent No 6,357,971 (to Rexius), discloses a truck with a fluid tank and a mixing tank for mixing material (e.g., seeds, fertiliser) with water immediately prior to application. However, each of the above inventions relate to application of coarse particulate 5 material, either dry or mixed with water, and therefore the distribution of material (e.g. fertiliser) on the ground is sporadic (in comparison with distributing the same quantity of fine particles). It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice. 10 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 15 number of prior art publications are referred to herein, this 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. It is acknowledged that the term 'comprise' may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this 20 specification, and unless otherwise noted, the term 'comprise' shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term 'comprised' or 'comprising' is used in relation to one or more steps in a method or process. 8 James & Wells Ref: 127948/62 Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only. DISCLOSURE OF INVENTION According to one aspect of the present invention there is provided a dispersion 5 system configured to be mounted on a vehicle, the dispersion system including a storage compartment for particulate material, a fluid storage tank, and an applicator configured to disperse a fine particle suspension, characterised in that 10 the dispersion system includes a processor configured to receive coarse particulate material from the storage compartment, and to process the coarse particulate material to form a fine particulate material for mixing with fluid from the fluid storage tank to produce a fine particle suspension for dispersion by the applicator. 15 According to another aspect of the invention there is provided a method of preparing particulate material for dispersal, the method including the steps of: a) processing the particulate material to form a fine particle suspension, and b) transferring the fine particle suspension to an applicator device, and c) dispersing the fine particle suspension with the applicator device, 20 the method characterised in that the steps a) to c) are performed on a vehicle. 9 James & Wells Ref: 127948/62 In a preferred embodiment the dispersion system is mounted on a spreader truck. However the dispersion system may be mounted onto any of the vehicles commonly used to distribute fertilisers and the like onto the ground. These vehicles include spray trucks and various self-propelled or towed vehicles, such as 5 modified trucks, tractors or trailers attached to same, for land-based applications. Hence, reference to a dispersion system mounted on a spreader truck only throughout this specification should not be seen as limiting. An advantage of mounting the dispersion system on a spreader truck is that these vehicles are commonly used for spreading particulate materials on relatively small 10 areas, such as individual paddocks, where other methods, such as aerial top dressing, are not practical or too costly. A spreader truck may also be used in situations where control of the dispersion is important, for example to minimise the amount of fertiliser entering waterways, or to restrict the amount of lime to a well defined region (eg roadway construction). 15 A storage compartment for the present dispersion system may be any container of a suitable size and configuration to carry particulate material. The storage compartment on a spreader truck is generally in the form of an open bin or hopper, being a container having an open top (for ease of loading material into the hopper) and sloping sides. The material in the hopper is commonly 20 removed from the region around the narrow base of the hopper. The sloping sides of the hopper aid movement of material in the hopper towards the base as material is removed from it. 10 James & Wells Ref: 127948/62 In some instances the material in the hopper may be removed by falling through an opening in the base of the hopper onto a system devised to transport the material (eg a conveyor belt, angled chute, auger etc). A typical spreader truck includes a hopper conveyor belt configured to collect 5 material from the base of the hopper and transport it to a spinner. In other cases a spreader truck may use an auger mounted in the hopper (instead of a conveyor belt) to carry the material out of the hopper. In a preferred embodiment the particulate material includes fertiliser granules. The dispersion system of the present invention may be used to disperse any 10 material in particulate form. However, it is envisaged that it may be used to advantage in application of fertilisers, including phosphate, lime, sulphur, nitrogen and trace elements and mixtures of them. In the context of the present invention a coarse particle may be considered to be any particle of dimension greater than 1 mm. Conversely, particle sizes of 15 dimension less than 1mm (typically in the order of 25 jj to 75 m) may be considered to be fine particles. Fertiliser granules, which size may range from around 3 mm to around 6 mm, are coarse particles. Some fertiliser components, such as Aglime and rock phosphate, are produced as ground solids, commonly sized around 1 mm to around 2 mm and 20 therefore also coarse particles. A fluid storage tank for the dispersion system may be an existing tank on a spreader truck or may be readily fitted to one, for example by mounting it on the 11 James & Wells Ref: 127948/62 side or rear of the hopper, or to the frame of the truck. The fluid storage tank stores water required for processing the granulated fertiliser. Ideally the size of the tank, or tanks, should be such that sufficient water is carried on the spreader truck to disperse the entire contents of the hopper without the 5 need for the tank(s) to be refilled. However, smaller tanks may be used and refilled as required. In preferred embodiments the applicator is a spinner. A spinner is preferred mainly because it is a relatively simple device that is commonly fitted to spreader trucks (and other land-based vehicles used to 10 disperse particulate materials). Making use of existing equipment on a spreader truck reduces the cost of modifications required to implement the present invention. A spinner operated in conjunction with the present dispersion system may also provide a distribution of fertiliser similar to that provided by other types of applicator, e.g., a spray system. 15 However, conventional spinners, usually in the form of spinning discs with a number of radially extending vanes, can result in break-up of the fine particle suspension, creating a mist of particles which can easily drift away from the intended dispersal area. This is undesirable as it can lead to fertiliser being deposited where it creates an environmental hazard, such as in or near waterways, 20 as well as creating a loss of fertiliser from the intended dispersal area, so that more fertiliser, at more cost, must be applied to achieve the correct application rate. In a preferred embodiment the spinner is an encapsulated spinner. 12 James & Wells Ref: 127948/62 Reference to an encapsulated spinner throughout this specification should be understood to mean a spinner in which the substance to be dispersed is enclosed in at least a portion of the spinner. Preferably an encapsulated spinner may include a central spindle. A central 5 spindle may be connected to a motor so as to rotate the spindle and encapsulated spinner in a manner similar to a conventional spinner. In alternative embodiments an encapsulated spinner may be configured to attach to a central spindle, where the central spindle may be connected to a motor. Preferably an encapsulated spinner includes a receiving portion configured to 10 accept material to be dispersed. In a preferred embodiment a receiving portion may be an annular collector centred on the spindle, the collector being configured to have a solid base and an open top opposite the base. Preferably an encapsulated spinner includes one or more spouts configured to 15 extend radially outwards from the outer side of the collector. Preferably the spouts may be in the form of open ended tapered funnels. The spouts may be connected to the collector at the wider end through an aperture in the outer side (with respect to the spindle) of the collector. In use the encapsulated spinner is oriented such that the open top of the collector 20 is facing upwards towards the source of material to be dispersed. The material to be dispersed may enter into the collector through the open side as the spinner is rotating. The material may then flow from the collector through an aperture into the spout under the influence of centrifugal force as the spinner rotates. 13 James & Wells Ref: 127948/62 An advantage of using an encapsulated spinner is that the material, once it enters into a spout, is contained (encapsulated) so that it flows through the spout to the outer opening from where it is dispensed. As a consequence of containment within the spout the material does not create a 5 mist, in contrast to conventional spinners where the material can be broken up by the sudden battering from the vanes as the spinner rotates, This may result in savings in the material to be dispersed, as there may be little of no drift, as well as limiting the spread of material to areas where it is not required or may be undesirable. 10 Furthermore, the tapered nature of the spout causes the material to accelerate as it moves along the spout, resulting in an increased spread of the material in comparison with a conventional spinner rotating at the same speed. The increased coverage may lead to lower application costs, for example as fewer passes need to be made by the spreader truck to cover an area over which the material is to be 15 dispersed (such as a paddock for example). In other embodiments the applicator may be a spray system. Spray systems may provide a uniform distribution of fertiliser (in suspension), especially if the system includes a plurality of nozzles aligned along a boom extending laterally from the spreader truck. 20 However, a spray system, including pump(s), hoses, nozzles and support structure may generally involve a higher capital outlay than a simple spinner applicator, which adds to the cost of applying fertiliser by this method. 14 James & Wells Ref: 127948/62 Specialised spray vehicles generally have a tank configured to hold a suspension or solution to be sprayed, rather than a hopper, making them less suitable for use with the present dispersion system. The improvement of the present invention over the prior art dispersion systems is 5 the use of a processor mounted on the spreader truck. The processor is configured to process the granulated fertiliser into fine particles which can be combined with fluid to form a fine particle suspension. In practice the processor is located between the hopper conveyor belt (used to carry the granules from the hopper) and the spinner. It may be possible to locate 10 the processor such that the hopper conveyor belt delivers the granules directly into the processor. However, in general a second conveyor belt (a processor conveyor belt), configured to lift the granules, may be required to transport the fertiliser from the hopper conveyor belt to the processor. Alternatively the granules may be transported to the processor by other means, such as an auger. 15 In a preferred embodiment the processor includes a mill. A mill is used to grind the coarse particles from the hopper into fine particles. There are various kinds of mill that can be used for this purpose, including hammer mills, ball mills, and disc mills. Rollers may also be used to crush coarse particles to a fine size. 20 In a preferred embodiment the mill is a hammer mill. A hammer mill has an advantage over other types of mill in that it may be used for grinding wet material. Other types of mill tend to clog up when grinding wet material which may lead to stoppages while the mill is cleaned. 15 James & Wells Ref: 127948/62 In a preferred embodiment the size of the fine particles after processing in the hammer mill is in the range 75 p to 25 p. In a preferred embodiment the average size of the distribution of fine particles is around 50 p. 5 Water from the fluid storage tank is added to the fine particles in the processor to form a fine particle suspension. Reference to a fine particle suspension throughout this specification should be understood to refer to a mixture of two substances, with the character that one does not rapidly settle out. In the present example the two substances are water and fertiliser in the form of 10 fine particles. As most fertiliser compounds are soluble in water, a fine particle suspension of fertiliser should be understood to include fertiliser in solution. The amount of water added is adjusted to provide a fine particle suspension of a consistency that may be applied effectively by a spinner. In a preferred embodiment around 15 to 30 litres of water is added per 100 kg of 15 fertiliser. For most fertiliser material a mixture equivalent to around 20 litres of water per 100 kg of fertiliser produces a fine particle suspension of a consistency suitable for application by a spinner. The ratio of water to fertiliser, however, does depend on the nature of the fertiliser 20 material. For example, fine particles of rock phosphate are relatively insoluble in water and form a fine particle suspension of suitable consistency with relatively little water (around 15 litres per 100 kg). However, most fertiliser components 16 James & Wells Ref: 127948/62 absorb water, so that more water (around 20 -30 litres per 100 kg) is required to produce a suitable consistency for application by a spinner. The water may be added before, during or after the milling of the particles. In a preferred embodiment water is added to the coarse particulate material as it 5 enters the processor. Water may be sprayed onto the granules as they enter the processor, immediately prior to entering the hammer mill. With this arrangement water inevitably is combined with the fertiliser during the milling process. A significant advantage of wet milling is that it reduces the amount of dust created 10 by the milling process, thus reducing random dispersion of the fertiliser, wastage and other potential hazards (e.g., inhalation of caustic materials etc). In a preferred embodiment the dispersion system includes at least one additive storage tank. Other materials, such as weed killer, insecticide and nitrogen loss inhibitors, may 15 be added to the fine particle suspension in the processor. These materials, or additives, may be carried on a spreader truck in a separate additive storage tank and added to the fine particle suspension in the processor as required. The additive storage tank or tanks may be configured to contain additives in either particulate or liquid form, and may contain a mixture of additives 20 or a single additive only. For example, it may be preferable in some situations to keep the various additives separate until just before application, in which case the additives may be stored in separately additive storage tanks and added into the processor as required. 17 James & Wells Ref: 127948/62 One advantage of this is that the additives may be combined into the fine particle suspension only when required for a particular application, or application area. This may avoid wastage in comparison with incorporation of additives into a whole batch of pre-mixed fertiliser and consequently applying additives where they are 5 not needed. Mixing in the additives only as required may save on costs of materials and avoid dispersal of additives where they are not required or potentially harmful, as for example may occur if weed killer is being used. A further advantage is that the additives may be adjusted for dispersal over particular areas during a single application run, rather than requiring a separate 10 batch to be made for each area. For example, where weed killer is required in one area and not another, a dispersal system according to the present invention could disperse the fine particle suspension including weed killer over one area, then, after switching off supply of weed killer to the processor, continue dispersal over another area. 15 In a preferred embodiment the fine particle suspension exits the processor through a screen located in the vicinity of the base of the processor. During the processing operation the processor contains suspended fertiliser having particles with a range of sizes. A screen of an appropriate mesh size is used to allow a suspension of fine particles of the preferred size to pass through, while 20 returning larger coarse particles for further processing. In a preferred embodiment the mesh size of the screen is in the range 1 to 3 mm. A mesh size larger than 3 mm may allow a suspension containing too much coarse material to pass through the screen, resulting in poor distribution of the fertiliser onto the ground. 18 James & Wells Ref: 127948/62 A mesh size smaller than 1 mm may lead to clogging of the screen, resulting in costly delays during application while the screen is cleared. The processor may be situated such that the fine particle suspension leaving the processor through the screen falls directly onto the spinner, through the open top 5 of an encapsulated spinner for example, and is dispersed onto the ground. In other cases the suspension may be directed onto the spinner by other means, such as a chute or tube. A significant advantage of the present invention is that it allows a spreader truck, a vehicle commonly used to apply granulated fertiliser, to be readily converted to 10 apply fertiliser as a fine particle suspension. The advantages of using fine particle suspensions over granules are well known, and include a much more uniform distribution of fertiliser. For example, application of nitrogen products as a fine particle suspension is known to lead to improvement in the yield of crop or pasture by a factor of three or 15 more over application of the same amount of granulated product. Conversely, only a third as much product need be applied as a fine particle suspension in order to achieve the same yield as for granules. Another very significant improvement of the present invention is that processing the coarse particulate in a water solution reduces or eliminates the creation of 20 fertiliser dust. Not only does this reduce losses but also prevents the dust commonly associated with application of dry fertiliser from drifting away from the target area. The ability to reduce the amount of fertiliser applied, and to contain it in the target area, may be very significant advantages of the present dispersion system as 19 James & Wells Ref: 127948/62 attention is increasingly being paid to problems cause by excess fertiliser loading into the environment, especially in the vicinity of water ways. The use of an encapsulated spinner may: reduce the amount of fertiliser dispersed into unwanted areas and lower the 5 visibility hazard by reducing the incidence of drift; save material costs, by reducing waste; and saving application time and costs as the increased spread of coverage (in comparison with conventional spinners) means fewer passes need to be made to cover the intended dispersal area. 10 Processing coarse fertiliser on a spreader truck as part of the application process also means that the problems associated with producing, packaging, transporting and handling fine particle fertiliser prior to application are avoided. Avoidance of these problems by processing the coarse fertiliser as required immediately prior to application may lead to significant savings in the cost of fine particle fertiliser to the 15 user. Another advantage of the present dispersion method is that the application process may be stopped and started at any time without creating any of the problems generally associated with using fine particle suspensions. When required the process may be halted by stopping the hopper conveyor belt and the processor (ie, 20 spray unit and hammer mill), thus stopping production of the fine particle suspension. Any suspension remaining in the processor or on the spinner may be easily cleaned away by washing. The use of additive storage tanks provides the advantages of: 20 James & Wells Ref: 127948/62 • saving costs by only adding additives into the fine particle suspension when required; • reducing environmental damage by not adding additives where not required or potentially harmful; and 5 • saving time and cost as new batches of material (with or without additives) do not have to be mixed and applied separately. In this system the problem of fine particles settling out of suspension does not arise as the suspension is applied directly following its formation. This is in contrast to the situation that may arise when a fine particle suspension is produced 10 in bulk and loaded into a tank for subsequent application. Over time the fine particles may settle out, for example if left too long in the tank before application or between applications. Another advantage is that the water used to create the fine particle suspension may be sourced from near the application site. This means that the fertiliser may 15 be purchased and transported to the application site as dry, relatively (with respect to fine particle fertiliser) inexpensive granulated material, saving cost of processing and (in comparison with transporting a suspension) the cost of transporting water to the site. BRIEF DESCRIPTION OF DRAWINGS 20 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: 21 James & Wells Ref: 127948/62 Figure 1A shows a schematic side view of a dispersion system according to one embodiment of the present invention; and Figure 1B shows a schematic rear end view of the dispersion system shown in Figure 1 A; a;nd 5 Figure 2A shows a schematic side view of an encapsulated spinners according to one embodiment of the present invention; and Figure 2B shows a schematic plan view of the encapsulated spinner shown in Figure 1A. BEST MODES FOR CARRYING OUT THE INVENTION 10 A dispersion system according to one embodiment of the present invention is generally indicated by (1) in Figure 1. The dispersion system (1) is shown in Figure 1 mounted on a vehicle in the form of a spreader truck, generally indicated by (2). The dispersion system (1) includes a storage compartment for particulate material 15 in the form of a hopper (3) mounted on the spreader truck (2). The dispersion system (1) also includes a fluid storage tank in the form of a water tank (4) shown in Figure 1 mounted on a side of the hopper (3). An applicator in the form of a spinner (5) is mounted at the rear end of the spreader truck (2). In practice the spinner includes a pair of discs mounted side by 20 side at the rear of the spreader truck (2), as shown in the schematic rear end view in Figure 1B. 22 James & Wells Ref: 127948/62 The discs of the spinner are connected to a motor on the spreader truck (2). For clarity the motor connections to the spinner and the mounting of the spinner (5) and other components of the dispersion system (1) are not shown in Figure 1. A conventional spreader truck (2), as commonly used to disperse granulated 5 matter, includes a hopper (3) and spinner (5). In conventional use, fertiliser, in the form of granules, is loaded into the hopper (3). A hopper conveyor belt, of which only the end (6) extending outside of the hopper (3) is shown in Figure 1, is used to transfer the fertiliser from the base region of the hopper (3) to a position outside of the hopper where it falls onto the spinner (5). 10 The conveyor belt and spinner(s) are controlled by a computerised system so that the desired distribution (amount and spread) of fertiliser is applied as the truck moves over the ground. In the dispersion system (1) of the present invention fertiliser from the hopper conveyor belt (6) is diverted from the spinner (5) and into a processor (7). This is 15 achieved by a second conveyor belt, in the form of a processor conveyor belt (8), which collects fertiliser from the hopper conveyor belt (6) and transfers it into the open top of the processor (7). The processor (7) includes a hammer mill (not shown), which is driven by a hydraulic system on the spreader truck (2). Alternatively, an auxiliary motor may 20 be fitted to the processor to operate the hammer mill. The processor (7) also includes a spray unit (not shown) which is connected by a hose (9) to the water tank (4). 23 James & Wells Ref: 127948/62 The spray unit is located near the opening in the top of the processor (7) and is configured to spray water onto the granules of fertiliser as they enter the processor (7). Around 15 to 30 litres of water is added per 100 kg of fertiliser, depending on the nature of the fertiliser. For most common fertilisers the amount of water added 5 is likely to be around 15 to 20 litres per 100 kg of fertiliser. An additive storage tank (11) configured for storage of additives is mounted on the spreader truck (2). Various additives, such as (without limitation) weed killer, insecticide and nitrogen loss inhibitors, including urease inhibitor and DCD, can be stored as required in one or more additive storage tanks (11). 10 The additive storage tank (11 ) is connected to the processor (7) so that additives from the additive storage tank (11 ) can be delivered to the processor (7) through the opening in the top of the processor (7). For additives in liquid form the additive storage tank (11) can be connected to the processor's spray unit and sprayed onto the coarse particulate material as it enters the processor. 15 The water/granulated fertiliser/additives (if used) mixture falls from the top of the processor into a hammer mill where the mixture is wet ground to form a fine particle suspension. The base of the processor (7) includes a section configured as a screen (indicated by (10) in Figure 1) having a mesh size of around 1 mm to 3 mm. With a spinner 20 (5) formed as two discs, as shown in Figure 1, a section of the base of the processor (7) above each disc includes a screen (10). A spinner, in the form of an encapsulated spinner is generally indicated by arrow 11 in Figure 2. The encapsulated spinner (11) is mounted on a spindle (12) which 24 James & Wells Ref: 127948/62 is driven to rotate as indicated by arrow (19) (note the spindle can be driven to rotate in either direction). The encapsulated spinner (11) includes a receiving portion in the form of a collector, generally indicated by arrow 13. The collector (13) has a solid base (14) 5 and an open top (15) into which a material to be dispersed can enter the collector (13), as indicated by arrow 18. The region of entry of the material into the collector (13) is chosen, together with the rate of spin of the encapsulated spinner, such that the material is dispersed as intended behind the vehicle as it moves along. A spout in the form of an open ended tapered funnel (16) is connected to the 10 collector (13) by an aperture (17) in the outer side wall (22) of the collector (13). A material to be dispersed (not shown in this figure) enters through the open top (15) into the collector (13) as indicated by arrow 18. As the spinner rotates the material is moved through the aperture (17) into the tapered funnel (16) by centrifugal force. The material is accelerated as it moves down the tapered funnel 15 (16) until it exits through the opening (21) at the narrow end of the tapered funnel (16). A fine particle suspension containing particles sized between around 75 p to around 25 p moves through the screen (10) and onto the spinner. In normal operation the discs of the spinner (5) rotate at around 400 to 500 rpm. At such 20 speeds the fine particle suspension is spun out of the encapsulated spinner (5, 11) in the form of small droplets. The droplet size can be varied from a fine mist to "raindrop" size by varying the speed of the spinner (5, 11). The speed of the spinner (5,11) is chosen to provide a droplet size suitable to reduce or eliminate drift of the droplets away from the intended dispersal area. The fine spray of fine 25 James & Wells Ref: 127948/62 particles in suspension provides improved (more uniform) distribution of fertiliser with respect to distribution of granulated particles. Prior to and during application an operator can vary the viscosity of the fine particle suspension falling onto the spinner (5) by adjusting the flow rate of the water (and 5 liquid additive if used) sprayed onto the granules as they enter the processor (7). A similar arrangement to that described above is also used on a vehicle equipped with an applicator in the form of a spray unit. A processor as described above is used to provide a fine particle suspension of fertiliser with the required viscosity for the spray unit. A fine particle suspension for spraying will generally contain around 10 10 litres more water per 100 kg of fertiliser than a suspension of the same fertiliser for application by a spinner. 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 thereof as defined in the appended claims. 15 26 </div>

Claims

<div class="application article clearfix printTableText" id="claims"> James & Wells Ref: 127948/62 WHAT l/WE CLAIM IS:

1. A dispersion system configured to be mounted on a vehicle, the dispersion system including a storage compartment for particulate material, a fluid storage tank, and an applicator configured to disperse a fine particle suspension, characterised in that the dispersion system includes a processor configured to receive coarse particulate material from the storage compartment, and to process the coarse particulate material to form a fine particulate material for mixing with fluid from the fluid storage tank to produce a fine particle suspension for dispersion by the applicator.

2. A dispersion system as claimed in claim 1 wherein the fluid is water.

3. A dispersion system as claimed in either one of claims 1 or 2 wherein the applicator is a spinner.

4. A dispersion system as claimed in claim 3 wherein the spinner is an encapsulated spinner.

5. A dispersion system as claimed in any one of claims 1 to 4 wherein the processor includes a mill.

6. A dispersion system as claimed in claim 5 wherein the mill is a hammer mill. 27 NOW AMENDED

7. A dispersion system as claimed in any one of claims 1 to 6 inpfudjng at least one additive storage tank.

8. A dispersion system as claimed in any one of claims 1 t</7 including a screen located in the vicinity of a base of the processor.

9. A dispersion system as claimed in claim 8 wherein /he /iesh size of the screen is in the range 1 to 3 mm.

10. A method of preparing particulate material forfaisi^ersal, including the steps of: a) processing the particulate material witl/a fjtiid in a processor to form a fine particle suspension, and b) transferring the fine particle suspi^nsj^n to an applicator, and c) dispersing the fine particle suspension with the applicator, the method characterised in that tbie steps a) to c) are performed on a vehicle.

11. A method of preparing particulate material for dispersal as claimed in claim 10 wherein the vehicle is a spreader truck.

12. A method of preparing particulate material for dispersal as claimed in either one of claims 10 or 11 wherein the processor includes a hammer mill.

13. A method of preparing particulate material for dispersal as claimed in any one of claims 10 to w. wKerein the applicator is a spinner.

14. A methodyof preparing particulate material for dispersal as claimed in claim 13 wherein/theipinner is an encapsulated spinner 28 AS AMENDED

7. A dispersion system as claimed in any one of claims 1 to 6 including at least one additive storage tank.

8. A dispersion system as claimed in any one of claims 1 to 7 including a screen located in the vicinity of a base of the processor.

9. A dispersion system as claimed in claim 8 wherein the mesh size of the screen is in the range 1 to 3 mm.

10. A method of preparing coarse particulate material for dispersal, including the steps of: a) processing the coarse particulate material with a fluid in a processor to form a fine particle suspension, and b) transferring the fine particle suspension to an applicator, and c) dispersing the fine particle suspension with the applicator, the method characterised in that the steps a) to c) are performed on a vehicle.

13. A method of preparing particulate material for dispersal as claimed in any one of claims 10 to 12 wherein the applicator is a spinner.

14. A method of preparing particulate material for dispersal as claimed in claim 13 wherein the spinner is an encapsulated spinner. 28 James & Wells Ref: 127948/62

15. A method of preparing particulate material for dispersal as claimed in any one of claims 10 to 14 wherein the particulate material includes fertiliser granules.

16. A method of preparing particulate material for dispersal as claimed in any one of claims 10 to 15 wherein the fluid is added to the coarse particulate material as it enters the processor.

17. A method of preparing particulate material for dispersal as claimed in any one of claims 10 to 16 wherein additives are processed with the particulate material in step a).

18. A method of preparing particulate material for dispersal as claimed in any one of claims 10 to 18 wherein the size of particles in the fine particle suspension is in the range 75 \i to 25 |j.

19. A method of preparing particulate material for dispersal as claimed in any one of claims 10 to 18 wherein the average size of particles in the fine particle suspension is around 50 p.

20. A method of preparing particulate material for dispersal as claimed in any one of claims 10 to 19 wherein the fine particle suspension exits the processor through a screen located in the vicinity of the base of the processor.

21. A vehicle fitted with a dispersion system as claimed in any one of claims 1 to 9.

22. A dispersion system substantially as herein described with reference to and as illustrated by the accompanying description and drawings. 29 James & Wells Ref: 127948/62

23. A method of preparing particulate material for dispersal substantially as herein described with reference to and as illustrated by the accompanying description and drawings. BRETT ASHLEY EMENY by his authorised agents Intellectual Property Office of N.Z. 2 0 FEB 2008 RECEIVED 30 </div>