GB2551345A

GB2551345A - Agricultural sprayer

Info

Publication number: GB2551345A
Application number: GB1610272.5A
Authority: GB
Inventors: Kneen Andrew
Original assignee: HOUSEHAM SPRAYERS Ltd
Current assignee: HOUSEHAM SPRAYERS Ltd
Priority date: 2016-06-13
Filing date: 2016-06-13
Publication date: 2017-12-20
Anticipated expiration: 2036-06-13
Also published as: GB2551345B; GB201610272D0

Abstract

An agricultural sprayer having a boom with a plurality of nozzle locations spaced along the boom with a spray liquid being supplied to each location via a spray line 1. Each location is provided with at least two nozzles 2 connected to the spray line 1, each nozzle 2 having independently operable valves 3 to open and close the supply of liquid. A controller 5 is connected to each valve and programmable to open and close the valves 3. The valves 3 may be pneumatic valves, a supply of air to which is controlled by an electrically operable air valve in response to signals from the controller 5. The nozzles 2 at each location may be of different sizes, may produce different types of spray and may further be angled to direct the spray in different directions. In some embodiments there may be three or four nozzles at each location.

Description

AGRICULTURAL SPRAYER

Field of the Invention

This invention relates to an agricultural sprayer of the type having a plurality of individual spray nozzles spaced along a boom.

Background to the Invention

There is an increasing need for greater precision in the spraying of agricultural chemicals, whether for plant feeding or weed or pest control. Agricultural chemicals are costly and therefore need to be applied only where needed and only in the required dose. It is also very important to ensure that water courses and neighbouring land are not contaminated and so the wind dispersal of spray droplets needs to be taken into account.

Control of the spray nozzles has been undertaken by controlling groups of nozzles along the boom, for example groups of four or eight, each group being supplied through a respective flow control valve. This arrangement has the disadvantage that there is a lag in the build-up and dissipation of spray fluid pressure in each group, limiting precision of spraying. A more recent development is the individual control of the opening and closing of each nozzle, the nozzles being connected to common pressurised fluid supplies, again typically feeding groups of nozzles. The nozzles may be controlled by solenoid valves or by pneumatically-operated valves, for example.

While individual nozzle control permits a higher degree of precision, an individual nozzle can only handle a limited range of flow rates, and for different conditions, different nozzles may need to be fitted. This can sometimes be achieved by the mounting of a number of different nozzles on a rotatable turret, but it is still necessary to effect the changeover manually. One instance where widely differing flow rates might need to be achieved is in turning of the boom, where a significantly greater forward speed of the outer end of the boom is experienced as compared with the inner end of the boom on the turn. Since the flow rate needed to deliver the same coverage will increase with speed, it is impossible to deliver a consistent application rate during turning operations.

Summary of the Invention

The present invention provides an agricultural sprayer having a boom with a plurality of nozzle locations spaced along the boom and a spray liquid supply to each location, each location being provided with at least two nozzles connected to the spray liquid supply, each nozzle having an independently-operable valve to open and close the supply of liquid to the nozzle, and a controller operatively connected to each valve and programmable to open and close the valves at the location.

This may provide a wider range of spray rates at each location than can be provided by a single nozzle.

Preferably, each valve is a pneumatic valve, supply of air to which is controlled by an electrically-operable air valve supplied with a control signal from the controller. In this way, a greater force is available to open and close the nozzle to the flow of spray liquid, ensuring more rapid and positive control, while reducing the electrical supply needed; solenoid-operated liquid valves require greater electrical power, requiring greater power-generation capacity on the sprayer, as well as operating more slowly, reducing precision of control.

The nozzles at each location may be of different outputs and different types, for example one more suitable for reducing drift and one for producing a finer droplet for increased efficacy in low wind conditions, permitting different nozzles to be selected according to wind direction, geographical location, hazards, potential pollution risks and spray rate, ensuring that spray drift is minimised, for example by means of GPS-based location. Preferably, the nozzles at each location are of different sizes and thus flow rates, i.e. having differing through bores, so that, rather than simple multiples, a wide range of flow rates can be achieved by using one or other nozzle, or both together. The use of three or four different nozzles at each location may permit an even wider range of flow rates by allowing any one of the nozzles or any combination of the nozzles to be utilised instantly. At least one of the nozzles at each location may be configured to generate a different type of spray from the others, for example producing a spray with different droplet sizes.

The sprayer may be a self-propelled sprayer, a trailer-mounted sprayer or a tractor-mountable sprayer unit.

Brief Description of the Drawings

The drawing is a diagram representing, by way of example, the arrangement of nozzles at a particular location on a spray boom of a sprayer according to one embodiment of the invention.

Detailed Description of the Illustrated Embodiment

In the drawing, a single location on a spray boom is represented; a practical agricultural sprayer will typically have a pair of foldable booms extendible on opposed sides, each boom having a plurality of spray lines supplied with the spray liquid under pressure from the sprayer liquid tank by a pump (not shown). The diagram shows a portion of one spray line 1, to which are connected a pair of nozzles 2 via pneumatically-operated valves 3, each connected to a compressed-air supply (not shown) through pipes 4. A controller 5 provides electrical signals on wires 6 to each valve 3 to operate a solenoid pilot air valve to supply air to the respective pneumatic valve. In this way, rapid opening and closing of the liquid valves can be achieved, the pneumatic valves delivering a high force in each direction, but not depending on the build-up and release of pressure in a long control line. The routing of electrical signal wires to the individual valves is easier than for individual pneumatic lines, while requiring a relatively low current to actuate the pilot valves, compared with the current that would be required to operate a direct-acting electrically operable valve.

The nozzles 2 are suitably of different bore so as to deliver different liquid flow rates. In this way, the two nozzles (A and B) potentially deliver at the individual location on the boom four different states, namely: 1. no flow; 2. nozzle A range of flows; 3. nozzle B range of flows; 4. nozzle A + nozzle B combined flow.

It will be appreciated that by using more than two nozzles, a greater number of states can be selected. In addition, or alternatively, the nozzles may be directed in different directions, for example to project the spray forwardly relative to the direction of travel or rearwardly. This may permit selective control to suit wind or other ambient conditions, or could be used to ensure application of spray liquid to the crop in different directions to improve coverage on leaves, for example. Alternatively, there may be nozzles of differing types, which can be selected according to crop type or geographical area or to control drift to sensitive areas.

The controller is suitably a programmable device which can control the nozzles to deliver a precisely metered dose of the spray liquid across a crop with a resolution of a square metre or less, under GPS control and according to crop or soil data previously mapped for the field in which the crop is growing. A variable rate application (VRA) can be utilised across the boom, so that following a VRA prescription map or similar the boom application rate can differ across the total width by selecting different nozzles at individual locations across the boom, increasing accuracy of application and placement, as well as reducing wastage of products such as liquid fertiliser or other agrichemicals. The controller can also ensure that the dosage is controlled to prevent over- or under-application during turning of the sprayer at the field end, and to prevent application near to water courses, footpaths and the like.

Claims

1. An agricultural sprayer having a boom with a plurality of nozzle locations spaced along the boom and a spray liquid supply to each location, each location being provided with at least two nozzles connected to the spray liquid supply, each nozzle having an independently-operable valve to open and close the supply of liquid to the nozzle, and a controller operatively connected to each valve and programmable to open and close the valves at the location.

2. An agricultural sprayer according to Claim 1, wherein each valve is a pneumatic valve, supply of air to which is controlled by an electrically-operable air valve supplied with a control signal from the controller.

3. An agricultural sprayer according to Claim 1 or 2, wherein the nozzles at each location are angled to deliver the spray in different directions from each other.

4. An agricultural sprayer according to Claim 1, 2 or 3, wherein the nozzles at each location are of different sizes from each other at the location.

5. An agricultural sprayer according to any preceding claim, wherein at least one of the nozzles at each location is configured to generate a different type of spray from the others.

6. An agricultural sprayer according to any preceding claim, comprising three or four nozzles at each location.

7. An agricultural sprayer, substantially as described with reference to the drawing.