GB2571268A

GB2571268A - Crop sprayer spraying and flushing system

Info

Publication number: GB2571268A
Application number: GB1802760.7A
Authority: GB
Inventors: George Knight Brian
Original assignee: Knight Farm Machinery Ltd
Current assignee: Knight Farm Machinery Ltd
Priority date: 2018-02-21
Filing date: 2018-02-21
Publication date: 2019-08-28
Also published as: GB201802760D0

Abstract

A crop sprayer 1 spraying and flushing system comprises a main tank 2 for solution to be sprayed and a first set of pipework connecting the tank to nozzles 9. The pipework comprises a pump 3 for driving the contents of the tank to the nozzles. The system comprises a cleaning fluid tank 16 for containing a fluid and a second set of pipework for connecting cleaning fluid to elements of the first set of pipework or the main tank. The cleaning fluid tank is selectively connected to the main tank via a flush supply line, a second pump 17, a cleaning fluid supply line and a main tank washing valve 29. The cleaning fluid tank is also selectively connected to the nozzles via the flush supply line, the second pump, the cleaning fluid supply line and a flush valve, whereby the cleaning fluid can be pumped by the second pump to selectively flush the main tank or the flow lines to the nozzles when the second pump is operational and the main tank wash valve and the flush valve.

Description

CROP SPRAYER SPRAYING AND FLUSHING SYSTEM

The present invention relates to a crop sprayer spraying and flushing system. In particular, it relates to an arrangement for the flushing out of a crop sprayer at or towards the end of spraying a field.

The agriculture industry is under constant environmental pressure to use chemicals such as plant protection products more sparingly and more efficiently, with less wastage. As a result, it would be desirable to reduce the amount of residue left in the system of an agricultural crop sprayer at the end of each application job or tank load, so that it is not wasted. Reducing the residual volume also reduces the amount of washings which, in turn, helps the environment.

The amount of residue can be proportional to the amount of pipework fitted to the machine. It is therefore also desirable to provide a fluid system within the crop sprayer that is volume (or pipe length) efficient.

Due to efforts to increase productivity, and also to avoid greater areas of ground compression, there has been a trend towards larger crop spraying machines which have wider spray booms. Total spray boom widths in excess of 36m are now commonplace. However, the wider the spray boom, the greater the length, and usually the volume, of its plumbing. Also, in order to supply enough fluid for a wider spray boom, it is necessary to increase the size of the fluid delivery plumbing, and that further increases the potential for additional residue.

It is accepted that an economic and relatively environmentally friendly solution to minimising disposal or wastage from chemical residue is to apply as much of the active ingredient as possible from the tank of the sprayer to the intended target, and to minimise the amount of plumbing.

The current invention recognises that where further reduction of the plumbing size is not practical, there can be solutions involving exchanging the fluid within some parts of the plumbing for a more environmentally friendly alternative. For example, there might be plumbing for the washing or flushing system of the crop sprayer, and it only has clean water in that sprayer washing system.

Traditionally, however, the plumbing system can contain chemical during spraying and water during washing. Nevertheless, avoiding contamination of the washing system with chemical at any time would reduce the volume of contaminated plumbing and thus would improve the efficiency of the washing systems.

The operator of a crop sprayer will normally operate it on a particular job, such as spraying one or more fields with pesticide, fungicide, weed killer (or herbicide) or fertiliser. At the end of a job, or more frequently if required, the operator will normally wash out the sprayer. This avoids sedimentation of the chemical in the pipework and, more importantly, prevents chemical contamination from one crop type to another.

Traditionally water or a suitable cleaning fluid has been used in the washing operation but the washing process is normally carried out independent of the chemical application process.

Attempts have been made to introduce clean water during the spraying process, i.e. while applying the spray to a crop, as this can flush out as much chemical as possible. However, this dilutes the active ingredients and therefore affects its performance. It is known that chemicals should only be applied at the recommended application rate.

The present invention seeks to provide a form of crop sprayer flushing system that addresses one of more of the above issues.

According to the present invention, there is provided a crop sprayer spraying and flushing system comprising:

a main tank for the chemicals or other solution to be sprayed and a first set of pipework connecting the main tank to at least one nozzle 9 for spraying the contents of the main tank, wherein the pipework comprises:

a pump for selectively driving the contents of the main tank to those nozzles, a feed portion extending from the main tank towards the pump, further pipework leading from the pump towards a splitter that diverts flow down a first flow line branch that leads towards a loop that feeds the nozzles, the splitter also being selectively able to divert flow down a second flow line branch, also connected to the loop, at the other end of the loop, for selectively also feeding the nozzles, the selection being controlled by a cycle select valve for selecting the direction of flow through the second flow line branch, such that it either flows from the splitter and down the second branch to the loop, or it instead flows up the second branch from the loop and onto a second return line for reverting the flow to the main tank;

the system further comprising a cleaning fluid tank for containing a cleaning fluid for cleaning the system and a selectively connectable second set of pipework for selectively connecting cleaning fluid from the cleaning fluid tank to elements of the first set of pipework or the main tank, wherein:

the cleaning fluid tank is selectively connected to the main tank via a flush supply line, a second pump, a cleaning fluid supply line, and a main tank washing valve; and the cleaning fluid tank is also selectively connected to the first and second flow line branches and thus the loop, via the flush supply line, the second pump, the cleaning fluid supply line and a flush valve, and further selectively to the second return line via additionally the cycle select valve, whereby the cleaning fluid can be pumped by the second pump to selectively flush the main tank or the first flow line branch, the second flow line branch and the loop, or the first flow line branch, the second flow line branch, the loop and the second return line, when the second pump is operational and the main tank wash valve, the flush valve, and the flush valve and the cycle select valve are switched to their appropriately open conditions.

With this arrangement, multiple parts of the “dirty side”, i.e. the first set of pipework, and the main tank, all of which carries the various chemical mixtures or solutions for spraying on a crop, can be selectively flushed with the cleaning fluid - preferably water or a cleaning solution, from the cleaning fluid tank, also known as the clean water tank. The pipework of that clean water tank and the cleaning fluid tank can instead be referred to as the clean side of the system, i.e. the second set of pipework and its cleaning fluid tank.

Preferably in the crop sprayer application system, the first set of plumbing, further comprises a first return line, connected to a pressure filter via a pressure regulator, the return line being connected to the feed portion of the first set of pipeline at one end and at its other end it is connected to the pressure filter, which is fitted between the flush valve and the first pump, whereby over pressure fluids being pumped by the pump through to the splitter, the first flow line branch, the second flow line branch and the loop can be avoided by excess pumped fluid being returned back to the feed portion of the first set of pipework, between the main tank and the pump.

Between the first pump and the main tank, and downstream of the connection of the return line to the feed portion, a supply valve can also be provided, which can selectively disconnect the pump from the main tank.

With this arrangement, when the flush valve connects the cleaning fluid supply line to at least the first flow line branch, the “dirty side” pump can return chemicals within its remaining pipeline system back to the pump inlet and the main tank.

Preferably the supply valve can selectively connect the pump, to the main tank or to an alternative fluid supply, such as a mains water supply or an alternative water or fluid supply, for tank filling and to wash through that part of the system, as then operated by the pump through the return line.

Preferably a boom arm feed flow meter, or a first flow meter, is provided between the flush valve and the splitter, to measure the clean fluid passing from the cleaning fluid supply line through the splitter. By measuring the volume, and knowing the internal volume ofthe pipework on the boom ofthe crop sprayer downstream therefrom, i.e. the first and second flow line branches and the loop, a pre-set volume can be allowed through corresponding to that known internal volume, so as to minimise or prevent flow of cleaning fluid through the nozzles and onto the crops.

Preferably the main tank wash valve has a flow meter provided therefor for measuring the volume of cleaning fluid passed into the main tank by the second pump. This flow meter is hereinafter the second flow meter as it is preferred that both flow meters described above are included.

This second flow meter allows a volume of cleaning fluid to be known whereby when it is for example water, its dilution of the mixture or solution in the main tank can be known, and thus the flow rate onto the crops can be adjusted accordingly to ensure appropriate dosage of the crop of the active substance in the mixture or solution.

Preferably the water flowing through the main tank wash valve into the main tank passes through a single or plurality of tank cleaning heads to spray water into the main tank in desired directions, thus assisting with cleaning thereof or flushing wasted chemical off the walls thereof for use in further spraying procedures.

Preferably the second return line connects with a filling hopper for enabling new chemical mixtures or solutions to be added to the main tank. This can be via return flow from the boom arm and can operate from the chemical system or the clean water system.

Preferably filters are provided in the pipework both from the main tank and from the clean fluid tank.

Straight flow filters and/or as already described for the first pumps system, a pressure filter with an associated pressure regulator, may be provided for either or both sets of pipework. The sprayed fluid, and the cleaning fluid, may thus be filtered after it exits its respective tank before distribution further around the system. This minimises the chance of blockages of the nozzles.

Preferably the cleaning fluid supply line from the second pump to the flush valve passes through a second pressure filter provided in that cleaning fluid supply line. Preferably it is before any hopper supply line. After the second pressure filter, the flow line therefrom to the flush valve is a filtered cleaning fluid supply line.

Preferably the hopper supply line is provided off the cleaning water supply line, between the second pump and the flush valve, and more preferably between the second pressure valve and the flush valve, whereby cleaning fluid - usually water can be supplied to the filling hopper. As such, the filling hopper can produce a premixed mixture or solution, or mixed on the machine.

The crop sprayer flushing system can also be provided with a tank selection control valve. It is connected in a flow line between the two tanks, the part extending to the cleaning fluid tank being a part of the third return line. It is arranged to select a flow direction for fluid coming from the second pressure filter via a second pressure regulator 25. With this, any flushing flow from the pressure filter, which flow is cleaning fluid, can be diverted either into the main tank or the cleaning fluid tank.

Preferably the flush supply line between the cleaning fluid tank and the second pump is fitted with a second directional valve for switching between a connection to the tank and an alternative fluid supply, such as a mains supply or an alternative tank of fluid. With this and the tank selection control valve, the second pump can suck that alternative fluid into the system and around to the tank selection control valve to enable that alternative fluid or mains water to be pumped into either of the cleaning fluid tank or the main tank. This will normally be done while the flush valve and the main tank wash valve are closed with respect to the first set of pipework and the main tank, respectively but can be used as an alternative supply for the described flushing procedures.

Preferably, inline filters are provided in advance of either or both of the pumps.

It will be appreciated that all or only some of the above described features can be provided in the provision of a system of the present invention.

The various aspect and features of the present invention, as discussed above and below, have a number of preferred aims. Firstly, to enable use of a substitute fluid (usually clean water) in substantially all parts of the crop sprayer’s plumbing where plant protection products are not required. Secondly, at or near the end of the main tank volume, allow the spraying operation to continue with a precise volume of clean water metered into the system to displace the plant protection product stuck within the system with the intention of not diluting it to a very low strength, or to diluting it by a known amount.

In order for the sprayer to run empty at the correct point for the washings to be introduced it is necessary to make a calculation based on the residual volume and the chemical application rate. It is therefore desirable that the operation is managed by the main application computer but it is also foreseen that the operator could manually select the changeover point.

The following ways to use the new system are envisaged.

1. When application of a main tank load is complete but it is intended to replenish it with a further load of compatible product, the system would be programmed to conduct a line purge to the point that clean water would dilute the application rate and then to continue with a clean water line flush, returning the clean water to the main spray tank for inclusion in the next load.

2. After the lines have been flushed with clean water the spray nozzles may be activated for a short burst to purge chemical residue from them.

The above preferred steps, particularly the first, will greatly reduce the accumulation of sediment within the spray lines, with the second step adding this function to the spray nozzles.

3. When application of a tank load is nearing completion and this coincides with the end of the job, the sprayer could be programmed to turn on the rinse heads in the main tank and to introduce a precise volume of clean water into the main tank via the tank rinsing system. At the same time, the chemical application rate would be proportionally increased to ensure the correct amount of active ingredient is applied to the crop. This process could then be followed by line flushing as previously described.

4. Once the job is complete and as much chemical as possible is displaced without affecting the dilution of the spray nozzle output the machine would then be washed out with a manual or automated wash cycle. Connecting the valves, splitter and pumps to an electronic controller can facilitate this by automating use of the methods discussed above and below.

The amount of active ingredient in the washings would be significantly reduced by the above preferred processes.

5. When filling the sprayer, the ‘clean water pump’ can be used to fill the on-board clean water tank. When this tank is full the ‘clean water pump’ can be diverted to fill the main tank, thereby increasing the filling speed thereof.

Additional preferred features of the present invention include the processes of:

a) Continuing to spray at the correct application rate whilst filling the lines (pipework) with an alternative fluid - to flush them; and/or

b) Continuing to spray at the correct product dose rate whilst washing the walls of the chemical tank; and/or

c) Measuring the washing water by volume as it is introduced into the chemical system for washing; and/or

d) Automatically adjusting the application rate to compensate for the introduction of a measured amount of clean water through the tank wash system; and/or

e) Automatically flushing the spray lines with clean water at the end of a job; and/or

f) Automatic flushing of the spray nozzles with clean water; and/or

g) Restricting the contents of the sprayer’s washing system to water or cleaning fluid only.

The present invention is therefore also directed to a method of using the system for providing any one or more of the functions described herein.

For example, but not exhaustively so, there can also be provided a crop sprayer spraying and flushing system as discussed above or below, arranged to apply product at the correct rate whilst system cleaning simultaneously takes place by increasing the flow rate through the nozzles to compensate for reduced dilution by virtue of added cleaning fluid.

Another examle could be a crop sprayer spraying and flushing system as discussed above or below where the cleaning cycle is automated by an electronic controller connected to the valves and pumps.

These and other features of the present invention will now be described in greater detail, purely by way of example, with reference to the accompanying drawings in which:

Figure 1 is a schematic representation of a sprayer control system for a crop sprayer comprising a crop sprayer flushing system in accordance with the present invention, in which crop spraying is currently occurring;

Figure 2 is a schematic representation of the sprayer control system of Figure 1 showing a first form of chemical flush back to a main tank of the crop sprayer;

Figure 3 shows the sprayer control system illustrating operation of a main tank rinsing or washing system using tanked water;

Figure 4 shows the sprayer control system illustrating spraying from the clean water tank and thereby flushing of the dirty lines up to the point of clean water reaching the spray nozzles.

Figure 5 shows the sprayer control system illustrating operation of a separate water supply flush of a first part of delivery pipes for the chemical spraying system;

Figure 6 shows the sprayer control system illustrating operation of a means for filling the tanked water supply tank from a separate water supply;

Figure 7 shows the sprayer control system illustrating how a separate water or fluid supply can also fill the main tank of the crop sprayer, thereby providing faster tank filling.

Figure 8 shows the spray boom lines being flushed back to the main tank with fluid from the clean water supply pump.

Figure 8 shows the sprayer control system illustrating a means of flushing the chemical spray system with clean water and returning this back to the main chemical tank.

Figure 9 shows a general form of a typical crop sprayer into which the system of the present invention could be installed.

Referring first of all to figure 1, there is shown schematically the pipework within an agricultural crop sprayer 1. Conventionally agricultural crop sprayers 1, including products generally as shown in figure 8, are vehicle mounted, whereby they are integrated into a dedicated vehicle. However, some are instead towed by a tractor, and thus are instead either wheel mounted, or arranged to be carried to a three point hitch at the rear of a tractor. Some are even mounted at the front of a tractor.

The crop sprayer 1 comprises a source of spray liquid - the main tank 2, connected by a first arrangement of pipework, including a feed portion 8a, to a pump 3 and thereafter to a spray nozzle 9, or as illustrated, a set of spray nozzles, via flow line branches 8b, 8c and a loop 8e, so that a required spray liquid can be applied to a crop from the main tank 2.

As shown in Figures 1 to 8, the various lengths or sets of pipework 8 are illustrated by lines. Where they cross over in the figures, they do not mix as the runs are not interconnected at those crosses.

The first arrangement of pipework comprises the feed portion 8a which connects the main tank 2 with the pump 3 via a supply valve 12, which can be of a directional or diverting type, and a suction filter 5. Downstream of the pump 3 is positioned a pressure filter 13. A flushing flow from the pressure filter 13 passes to a pressure regulator 4 which maintains the desired pressure in the supply to the nozzle(s) 9 by passing any surplus fluid via a return line 8d back to the feed portion 8a for recirculating as necessary through the pump 3, or if appropriate, for returning to the main tank 2.

The fluid that passes through the pressure filter 13, which has now been filtered to avoid or minimise potential blockages of the nozzle(s) 9, then communicates with a first of the flow line branches 8b. It extends onto a boom arm 30 of the sprayer 1, the boom arm 30 being better shown in figure 8. The first flow line branch 8b then communicates with the loop 8e on the boom arm, or a part thereof, and it feeds the nozzles to provide a spray line 31 from the boom arm 30, as in this embodiment, and generally, there are a plurality of nozzles 9, which when spraying will be in an open condition. The line is shown as straight, but other shapes or patterns can instead be provided for the nozzle arrangement.

The loop 8e, in practice, may be arranged to extend along the spray boom 30, although sometimes there are more than one such loop 8e as the fluid flow to the boom arm, or along the boom arm, might be split into a number of sections along the boom arm. This can be beneficial given the long length of the boom arms in many commercial agricultural sprayers, and even the foldability of those fold arms, whereby perhaps one loop might be provided for each foldable section of each boom arm 30.

Before flowing onto the boom arm 30, the spray fluid in this embodiment will pass through a flow meter 15, so that the quantity of fluid entering the boom arm 30 is known.

The fluid that passes through the pressure filter 13 towards the first flow line branch 8b passes a splitter 32 to create two flow lines towards the boom arm 30. This results in two flow lines, although the second is switchable on and off as a feed line, as the second flow line branch 8c is connected from the splitter 32 via a cycle select valve 7 a directional, or diverting, valve, which can serve to redirect flow differently around the crop sprayer’s system depending upon its setting.

The second flow line branch 8c is shown in parallel to the first flow line branch 8b. However, different routes on the sprayer 1 may be taken.

The second flow line branch 8c is connected to the opposite end of loop 8e to line 8b. Thus, when the splitter 32 connects the second flow line branch to the fluid source, as appropriate during spraying, the spray fluid passes through both flow branch lines 8b and 8c to loop 8e and thence to the spray nozzles 9. This thus assists with maintaining a reasonably constant pressure across all the nozzles 9, from one side of the loop 8 to the other.

Referring next to Figure 2, the cycle select valve 7 is operated to redirect the flow along the second flow line branch and away from the splitter. This is a likely condition when the operator stops spraying.

In this condition, the cycle select valve 7 now directs the spray liquid back to the main tank via a second return line 11, connected between the cycle select valve 7 and the main tank 2. As a result, the second flow line branch 8c now functions as a return line as well, from the loop 8e, rather than feeding the loop with fluid. Usually in this condition, the spray nozzles 9 are also shut off.

Along the second return line 11, i.e. downstream of cycle select valve 7, a filling hopper 10 is provided by which additional chemical to be sprayed can be introduced to the apparatus. This is typically switchable to allow the introduction of new chemical when filling the main tank 2. A clean water supply 24 is provided at the hopper for rinsing the hopper after use and for rinsing out chemical containers.

From the above, and comparing Figures 1 and 2, it is clear that the cycle select valve 7 decides whether the fluid flows though both branches 8b, 8c to the loop - a spray cycle, or whether instead the fluid passes firstly down the first branch 8b to the loop, and then around the loop 8e, before then passing back up the second branch 8c and back to the main tank 2 via the second return line 11 - a flush cycle.

In the spray cycle, the two branches 8b, 8c being used allows the spray pressure to be relatively constant across the loop 8e when spraying, whereas the flush cycle allows a clean sweep through the two flow line branches 8b, 8c and the loop.

The condition of figure 2 - the flush cycle, is normally used during a pause in spraying as the liquid returning to the main tank 2 can assist with agitating the liquid in the main tank, thus ensuring a thorough mixing of the mixture or solution in all areas of the sprayer that contain chemical.

Referring to Figure 3, the clean water tank 16 is connected to a second pump 17 via a flush supply line 6a, a second directional valve 18 and a second filter 19. A second pressure filter 20 is positioned downstream of the pump 17, and a flushing flow from that second pressure filter 20 is arranged to pass to a second pressure regulator 26 which maintains the desired pressure in the clean water supply beyond the second pressure filter; the surplus fluid is passed back to the clean water tank 16 via a tank selection control valve 29 and a third return line 6b.

Filtered water, or cleaning fluid if instead in the clean water tank 16, continues from the second pressure filter 20 into a filtered clean water supply line 6c, which delivers the clean filtered water/cleaning fluid under pressure to the dirty (spray chemical) side 28 of the fluid system of the crop sprayer 1.

Although illustrated with the dirty side 28 on one side of the drawing, and a clean (clean water or cleaning chemical) side 27 on the other, it is to be appreciated that these can be located intermingled between one another on an actual crop sprayer 1.

A main tank wash valve 21 is also connected to the filtered water supply line 6c and is able to selectively direct or divert at least a part of this pressurised clean fluid flow to a tank cleaning head 23. This is shown to be via a second flow meter 22. The tank cleaning head 23 can comprise one or more nozzle to spray the inside walls of the main tank 2 to clean those walls.

The filling hopper 10 can also be supplied clean water via a hopper supply line 24, which is connected to the filtered water supply line 6c. This can be to clean the hopper 10 or to dilute a concentrate in the hopper 10.

During spraying, the second pump 17 will not always be active but will be run whenever required.

When the end of a spraying job approaches the second pump 17 and the main tank wash valve 21 can be manually, or automatically, via a spray computer, activated so that the tank cleaning head 23 will rinse the walls of the main tank 2 with a measured amount of water, by virtue of the second flow meter 22. The chemical application rate to the crop can thus be increased to compensate for the addition of this washing water.

For example, if the chemical tank has 500 litres remaining and 100 litres of water is added the rate will need to be increased by 20% to still provide the same amount of chemical to the crop. Therefore, if the normal application rate is 100 litres per hectare it will be increased to 120 litres per hectare once the wash cycle has completed, or it can be gradually increased during this process.

Figure 3 only shows the main tank wash process. This, combined with the spraying configuration of figure 1, would be the process referred to above.

Referring next to Figure 4, as the end of the contents of the main tank 2 approaches, the system can manually, or automatically via the spray computer, re-direct a flush valve 14, in the line between the first pump 3 and the splitter 32, to introduce clean water to the two flow line branches 8b, 8c, and the loop 8e. This enables a clean water flush of those parts of the system. This can be sufficient to cause the spray line 31 to form, as shown thus also cleaning the nozzles 9, or it can be a controlled volume, measured by the flow meter 15 also in that line, so as to flush to the point of exiting the nozzles, or thereabouts.

This process can be timed too, so as to ensure that the flushings go on the field, but that the clean water does not. For example, if the flow line branches 8b, 8c and the loop 8e contain 100 litres of product/liquid in total, and the current application rate is 100 litres per hectare, this flush process could ideally be activated when one hectare remains to be sprayed.

Closing the nozzles 9, and also switching the cycle select valve 7, further allows the clean water from the clean water tank to flow around the second return line 11 and into the main tank. This further flushes out the machine and returns the washings to the main tank 2 for use in the next load.

Some chemicals, however, may need to be flushed form the spay nozzles’ tips and this can be achieved with a small burst of clean water from the spray nozzles 9 after the flushing procedure described above has completed, or perhaps later in the flushing cycle. This can be accomplished manually or programmed into the flushing cycle.

On occasions when it is not desirable to return the final flushing’s to chemical tank 2 the flushing process can be manually or automatically stopped at any point before direction valve 7 rotates to the flushing position.

Referring next to Figure 5, a further feature of this illustrated embodiment is shown. As can be seen, chemical from the first pump 3 - in the dirty side 28 - can be redirected, automatically if desired, such as with the spray computer, to the feed portion 8a of the feed line from the main tank. This process can be for emptying the pipework. The fluid will be driven by the pump 3, with the supply valve 12 rotated to open to atmosphere, or to a clean water supply, either the mains or a water tank, such as the clean water tank, if a suitable additional line was fitted. The chemicals remaining in that area of pipework would then be pumped towards, and/or flushed to, the main tank 2 when the flush valve 14 is closed to that section, as per Figure 4, and as also shown in this figure

5. The chemicals flow there via pressure filter, by not passing through it, but instead down the flushing flow line to the pressure regulator 4, and then through the first return line 8d and thus to the main tank 2.

Referring next to Figure 6, a method of filling the clean water tank 16 is shown. In this method, the second pump 17 is used to fill the clean water tank 16 with clean water by directing the second directional valve 18 to draw water from point 25. That point can be another water source, or a mains water source. As can be seen, the tank selection control valve 29 is directed to flow into the clean water tank 16. As such clean water from point 25 flows through the second directional valve 18, through the second filter 19, driven by the second pump 17, up to the second pressure filter 20, down its flushing line to the second pressure regulator 26, through the tank selection control valve 29 and into the clean water tank 16.

Referring next to Figure 7, this is similar to Figure 6, but it is instead arranged to fill the main tank, 2, or to part top it up. The tank selection valve 29, located downstream of the second pump 17, can be directed to lead the pumped water into the main tank 12, for increased filling speed of tank 12.

Referring to figure 8, cycle select valve 14 introduces clean water into the feed to the spray boom 8c via the flow meter 15 and returns it to the spray tank 2 via the cycle select valve 7 and line 11 via the induction hoper 10.

A person skilled in the art will quickly recognise the potential for manual or programmable flushing possibilities with the arrangement of this system. This system can combine any one or more of the sequences or flushing/cleaning processed 5 described above. The invention is not limited to the combination of all of the processes described, although a most preferred embodiment combines them together into a single system, as shown.

Although reference has been made to clean water for the clean water tank, other 10 cleaning fluids can instead be used.

The present invention has been described above purely by way of example. Modifications can be made to the invention as defined in the claims appended hereto.

CLAIMS:

Claims

CLAIMS:

1. A crop sprayer spraying and flushing system comprising:

a main tank for the chemicals or other solution to be sprayed and a first set of pipework connecting the main tank to at least one nozzle for spraying the contents of the main tank, wherein the pipework comprises:

a pump for selectively driving the contents of the main tank to those nozzles via at least one chemical supply line, the system further comprising a cleaning fluid tank for containing a cleaning fluid for cleaning the system and a selectively connectable second set of pipework for selectively connecting cleaning fluid from the cleaning fluid tank to elements of the first set of pipework or the main tank, wherein:

the cleaning fluid tank is selectively connected to the main tank via a flush supply line, a second pump, a cleaning fluid supply line, and a main tank washing valve; and the cleaning fluid tank is also selectively connected to the nozzles via the flush supply line, the second pump, the cleaning fluid supply line and a flush valve, , whereby the cleaning fluid can be pumped by the second pump to selectively flush the main tank or the flow lines to the nozzles when the second pump is operational and the main tank wash valve and the flush valve, are switched to their appropriately open conditions.

2. The system of claim 2, wherein the pipework leading from the pump to the nozzles comprises a splitter that diverts flow down a first flow line branch that leads towards a loop that feeds the nozzles.

3. The system of claim 2, wherein the splitter is able to divert selectively flow down a second flow line branch, also connected to the loop, at the other end of the loop, for selectively also feeding the nozzles, the selection being controlled by a cycle select valve for selecting the direction of flow through the second flow line branch, such that it either flows from the splitter and down the second branch to the loop, or it instead flows up the second branch from the loop and onto a second return line for reverting the flow to the main tank;

4. The crop sprayer spraying and flushing system of any one of the preceding claims, wherein a boom arm flow meter, or a first flow meter, is provided between the flush valve and the spray nozzles, to measure the clean fluid passing from the cleaning fluid supply line into the chemical supply lines.

5. The crop sprayer spraying and flushing system of any one of the preceding claims, wherein the main tank wash valve has a tank wash flow meter provided therefor for measuring the volume of cleaning fluid passed into the main tank by the second pump.

6. The crop sprayer spraying and flushing system of any one of the preceding claims, wherein the filling hopper for enabling new chemical mixtures or solutions to be added to the main tank is supplied by clean water from the flushing system.

7. The crop sprayer spraying and flushing system of any one of the preceding claims, wherein a hopper supply line is provided off the cleaning water supply line, between the second pump and the flush valve.

8. The crop sprayer spraying and flushing system of any one of the preceding claims provided with a tank selection control valve connected in a flow line between the two tanks.

9. The crop sprayer spraying and flushing system of any one of the preceding claims, wherein the flush supply line between the cleaning fluid tank and the second pump is fitted with a second directional valve for switching the fluid source for the second pump between a connection to the cleaning fluid tank and an alternative fluid supply

10. A crop sprayer spraying and flushing system of any one of the preceding claims, when dependent upon claim 4, arranged to apply product at the correct rate whilst system cleaning simultaneously takes place by increasing the flow rate through the nozzles to compensate for reduced dilution by virtue of added cleaning fluid.

11. A crop sprayer spraying and flushing system of any one of the preceding claims where the cleaning cycle is automated by an electronic controller connected to the valves and pumps.

Intellectual

Property

Office

Application No: GB1802760.7

Claims searched: 1-11

Examiner: Mr Rhys J. Williams

Date of search: 10 August 2018

Patents Act 1977: Search Report under Section 17

Documents considered to be relevant:

Category Relevant to claims Identity of document and passage or figure of particular relevance X 1,2, 8 & 11 US 2017/0006852 Al (ENGELBRECHT) See figure 3 and note paragraph [0021], X 1,4, 5,8 & 11 US 2014/0252111 Al (MICHAEL) See figures 3 & 4 particularly. Note multiple tanks and pumps for spraying and rinsing. See reference to metering in paragraph [0021], X 1,2, 8 & 11 at least EP 3162207 Al (AMAZONEN-WERKE) See WPI abstract no. 2017-27447N and the figures. X 1,2, 8 & 11 at least. EP 2425714 A2 (EXEL) See WPI abstract no. 2012-C86926 and figure 1. X 1, 2, 4, 5, 8& 11 US 2012/0292402 Al (OTTO) See figure 18. Note spraying and rinsing circuits. X 1,2, 8 & 11 at least FR 2824449 Al (EXEL) See WPI abstract no. 2003-078324 particularly. Note spraying and flushing circuits.