GB2181974A

GB2181974A - Spraying apparatus

Info

Publication number: GB2181974A
Application number: GB08526291A
Authority: GB
Inventors: Gordon Ross Barnett
Original assignee: MICROCIDE Ltd
Current assignee: MICROCIDE Ltd
Priority date: 1985-10-24
Filing date: 1985-10-24
Publication date: 1987-05-07
Also published as: GB8526291D0

Abstract

Spraying apparatus suitable for spraying herbicides or fertilizers includes a fan positioned adjacent a spray nozzle to assist in the forward motion and atomisation of the sprayed droplets. The nozzles and fan may project at any angle such as downwardly or upwardly or horizontally. Two or more nozzles can share a single fan. The nozzles and fans may be mounted along a boom attachable to a tractor. Hydraulic drives for the fans can be connected in series to allow simultaneous changes of speed to be effected. Electrostatic means may be incorporated in conjunction with the fans to assist in droplet attraction to leaves of plants or the like. <IMAGE>

Description

SPECIFICATION Improvements in and relating to spraying apparatus Field of the invention.

This invention concerns spraying apparatus typically ot the type utilised for the application of fertilizers, herbicides, pesticides and the like.

Background to the invention.

Such apparatus is often designed to be mounted on the three point linkage conventionally available at the rear of the modern tractor or is mounted on a towable carriage for towing behind a tractor or the like. In order to cover a wide area on a single pass, a number of spray nozzles are conventionally mounted along a boom.

There are a number of inefficient factors associated with the normal hydraulic spray nozzle. Thus it has a very wide droplet size range emission which produces droplets too large for efficient deposition on the spray target and, at the other end of the droplet emission spectra, very fine droplets, subject to uncontrollable drift.

As a consequence, considerable quantities of liguid which should reach growing plants over which the apparatus is passing, does not arrive on target and is wasted.

It is an object of the present invention to suhstantially improve the inefficient and wasteful aspects of conventional pressure nozzle sprayers.

Summary of the invention.

According to one aspect of the present invention over at least some of the downwardly directed spray nozzles associated with spraying apparatus of the type descrihed, is mounted: a motor driven fan, adapted when operating to force air in a generally downward direction around the nozzle, the air stream serving to increase the downward component of motion of all liquid droplets, however small, emanating from the nozzle, and to assist in breaking up oversize droplets.

Preferably the fan includes at least one propellor having adjustable-pitch blades.

Conveniently the fans are driven by hydraulic motors which may be powered by hydraulic fluid under pressure from a pump driven hy a power unit mounted on a carriage on which the spray nozzles are themselves mounted, or by a power unit mounted on the towing vehicle such as a tractor.

Conveniently the motors are connected in series so that the speed of all the fans can be altered by simply controlling the pump flow rate or introducing a flow control valve in the fluid flow or return paths to or from the motors.

By providing a sufficient-number of such fan assisted nozzles along a boom, so generally uniform coverage can be achieved over the entire length of a boom.

In one embddiment of the invention, each of the spray nozzles along a boom may be crop vided with fan assistance.

In another embodiment alternate ones of the nozzles along a boom are fitted with fans and the intermediate nozzles are arranged to direct their spray into air streams of the adjoining fan assisted nozzles.

According to another aspect of the invention in spraying apparatus having a plurality of downwardly directed spray nozzles and fan means mounted above at least some of the said nozzles, adapted when operating to force air in a generally downward direction around the nozzles, the air stream serving to increase the downward component of motion of all liguid droplets, however small, emanating from the fan assisted nozzles and further assisting in breaking up oversize droplets, electrostatic means is provided in conjunction with at least some of the nozzles to further increase the attraction of the particles to the plants or other objects towards which the nozzles are directed. Electrostatic means may be associated with all of the nozzles or only some of the nozzles.

It has been found that by incorporating fan assistance together with electrostatic assistance, so an improved performance is obtained relative to electrostatic-only systems which tend to have restricted droplet penetration ability into heavy agricultural crop leaf canopies and in which electrostatically charged droplets also tend to be attracted only to the upper parts of plants of opposite plurality so that severe overdosing of the spray in sensitive growing tips of sprayed crops tends to occur.

The fan assistance serves a number of specific purposes.

1. The air blast from the fan shears the larger droplets to relatively smaller droplets.

2. The air blast captures all small droplets that have been generated (whether initially or by shearing) and directs them towards the target. Thus the fan assistance tends to overcome cross-wind effects which would otherwise disperse the cloud of droplets away from the region which is to be sprayed.

3. The air blast will cause leaves and foliage to part and turnover and creates sufficient turbulance within the crop canopy such that under-leaf coverage approaches upper leaf coverage.

4. The air blast minimises the effect of negative wind velocities and direction. Thus in areas of high prevailing winds, the fan assistance may make application economical and in gusty conditions can mean the difference between uniform dispersion and spotted control, as well as the control of aerial drift contamination by reducing cross wind effect.

5. The air blast reduces operator exposure by directing the chemical directly towards the ground and thus generally away from the operator.

6. In view of the better success rate, fan assistance can reduce the cost of the chemical for achieving a given exposure.

7. The air blast assists in producing deep penetration into a dense crop canopy without the use of excessively high pressures or excessive volumes of liquid. This can further reduce application costs.

8. The improved penetration and coverage can significantly reduce the volume of liquid required per acre thus allowing more acres to be covered from a single filling and reduce costs.

9. By using variable pitch blades, the air blast can be controlled to meet different environmental and crop conditions.

According to another aspect of the invention, the boom may be movable so as to enable the spray nozzles and fans where fitted, to be directed in directions other than downwardly. Thus the same apparatus can be used to spray horizontally or even upwardly as required for different crops.

Thus apparatus embodying the invention may be supplied for use in orchards, on nut plantations, in vineyards, and can also be used for spraying berrys and citrus fruits as well as plants growing relatively close to the ground.

The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a perspective view of apparatus incorporating the invention.

Figure 2 is a diagrammatic view of part of the apparatus shown in Figure 1, Figure 4 is a similar perspective view to that of Figure 3 but with parts of the equipment removed for clarity and drawn to an enlarged scale, Figure 5 is a diagrammatic view showing an alternative arrangement in which spray nozzles with fan assistance are located alternatively to conventional nozzles, Figure 6 illustrates the spray pattern and dispersion associated with fan assisted nozzles mounted along a boom, and Figures 7 illustrates the spray pattern obtained when alternative nozzles are not fan assisted.

Detailed description of drawings In Figure 1 a tractor 10 is shown carrying by means of arms 12 and 14 forming part of a three point linkage, a boom 16 and between the boom and the tractor a platform 18 carrying at least one drum 20 serving as a reservoir of liquid which is to be sprayed on a crop over which the tractor is driven.

At one end of the boom is located a pump 22 having flow and return pipes 24 for driving the pump by means of hydraulic fluid supplied under pressure from a pump (not shown) carried by the tractor and driven by the power unit of the tractor.

The pump 22 is supplied with a feed pipe 26 from the tank 20 and delivers liquid from the tank under pressure to a manifold line 28 which in turn supplies each of five nozzles (not shown in Figure 1).

Reference is made at this point to Figure 2 which shows diagrammatically the arrangement envisaged in Figure 1 in which branch pipes 30 and 32 supply nozzles 34 and 36 below the boom 16. Although not shown in Figure 2, the other three nozzles are supplied in a similar manner.

Above each nozzle 34 and 36 etc., is mounted a rotatable fan blade 38 and 40 each of which is driven by a hydraulic motor 42 and 44 respectively supplied with hydraulic fluid or air under pressure from a pneumatic source via a series pipeline 46, 48, 50 etc.

The speed of the motors 42, 44 etc., and therefore the fans 38 and 40, is controlled by the rate of flow of the fluid (oil or air) along the line 46, 48 50 etc. and this is adjusted by either adjusting the flow rate from a pump (not shown) driven by the tractor engine or by introducing a flow restrictor valve (not shown) in the supply to the lines 46, 48, 50 etc.

The fans are arranged to rotate in a direction so as to cause a downward draft of air and as a protection, each fan is surrounded by a cylindrical basket or cage typically of metal such as 52 and 54.

Figures 3 and 4 show one such fan assisted nozzle assembly in greater detail and reference is now made to these figures. The cylindrical cage 52 is carried by a pair of bridge members 56 and 58 which have down-turned ends two of which are shown at 60 and 62 in Figure 3 for securing as by welding to the periphery of the cage 52. Carried by the bridging members 56 and 58 is a plate 64 on which a hydraulic motor 66 is mounted with an upward shaft extending through the plate and having secured on its protruding lower region a central boss 68 of a variable pitch propellor assembly. The latter is held in position by means of a spring 70 itself held in position by means of a washer 72 and hexagonal nut 74 threaded onto a threaded section at the lower end of the output shaft from the motor. (see Figure 4).

The propellor is made up of two blades 76 and 78 which are rotatably fitted into supporting sleeves 80 and 82 which on tightening, grip the inboard ends of the blades 76 and 78 and hold them at the inclination which has been set.

In this way the pitch of the propellor can be adjusted. In known manner, by inclining the blades to a greater extent, so the air blast will be increased and by feathering the blades so that they are more nearly coplanar, so the air

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

5. The air blast reduces operator exposure by directing the chemical directly towards the ground and thus generally away from the operator.

6. In view of the better success rate, fan assistance can reduce the cost of the chemical for achieving a given exposure.

7. The air blast assists in producing deep penetration into a dense crop canopy without the use of excessively high pressures or excessive volumes of liquid. This can further reduce application costs.

8. The improved penetration and coverage can significantly reduce the volume of liquid required per acre thus allowing more acres to be covered from a single filling and reduce costs.

9. By using variable pitch blades, the air blast can be controlled to meet different environmental and crop conditions.

According to another aspect of the invention, the boom may be movable so as to enable the spray nozzles and fans where fitted, to be directed in directions other than downwardly. Thus the same apparatus can be used to spray horizontally or even upwardly as required for different crops.

Thus apparatus embodying the invention may be supplied for use in orchards, on nut plantations, in vineyards, and can also be used for spraying berrys and citrus fruits as well as plants growing relatively close to the ground.

The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a perspective view of apparatus incorporating the invention.

Figure
2 is a diagrammatic view of part of the apparatus shown in Figure 1, Figure 4 is a similar perspective view to that of Figure
3 but with parts of the equipment removed for clarity and drawn to an enlarged scale, Figure 5 is a diagrammatic view showing an alternative arrangement in which spray nozzles with fan assistance are located alternatively to conventional nozzles, Figure 6 illustrates the spray pattern and dispersion associated with fan assisted nozzles mounted along a boom, and Figures 7 illustrates the spray pattern obtained when alternative nozzles are not fan assisted.

Detailed description of drawings In Figure 1 a tractor 10 is shown carrying by means of arms 12 and 14 forming part of a three point linkage, a boom 16 and between the boom and the tractor a platform 18 carrying at least one drum 20 serving as a reservoir of liquid which is to be sprayed on a crop over which the tractor is driven.

At one end of the boom is located a pump 22 having flow and return pipes 24 for driving the pump by means of hydraulic fluid supplied under pressure from a pump (not shown) carried by the tractor and driven by the power unit of the tractor.

The pump 22 is supplied with a feed pipe 26 from the tank 20 and delivers liquid from the tank under pressure to a manifold line 28 which in turn supplies each of five nozzles (not shown in Figure 1).

Reference is made at this point to Figure 2 which shows diagrammatically the arrangement envisaged in Figure 1 in which branch pipes 30 and 32 supply nozzles 34 and 36 below the boom 16. Although not shown in Figure 2, the other three nozzles are supplied in a similar manner.

Above each nozzle 34 and 36 etc., is mounted a rotatable fan blade 38 and 40 each of which is driven by a hydraulic motor 42 and 44 respectively supplied with hydraulic fluid or air under pressure from a pneumatic source via a series pipeline 46, 48, 50 etc.

The speed of the motors 42, 44 etc., and therefore the fans 38 and 40, is controlled by the rate of flow of the fluid (oil or air) along the line 46, 48 50 etc. and this is adjusted by either adjusting the flow rate from a pump (not shown) driven by the tractor engine or by introducing a flow restrictor valve (not shown) in the supply to the lines 46, 48, 50 etc.

The fans are arranged to rotate in a direction so as to cause a downward draft of air and as a protection, each fan is surrounded by a cylindrical basket or cage typically of metal such as 52 and 54.

Figures 3 and
4 show one such fan assisted nozzle assembly in greater detail and reference is now made to these figures. The cylindrical cage 52 is carried by a pair of bridge members 56 and 58 which have down-turned ends two of which are shown at 60 and 62 in Figure 3 for securing as by welding to the periphery of the cage 52. Carried by the bridging members 56 and 58 is a plate 64 on which a hydraulic motor 66 is mounted with an upward shaft extending through the plate and having secured on its protruding lower region a central boss 68 of a variable pitch propellor assembly. The latter is held in position by means of a spring 70 itself held in position by means of a washer 72 and hexagonal nut 74 threaded onto a threaded section at the lower end of the output shaft from the motor. (see Figure 4).

The propellor is made up of two blades 76 and 78 which are rotatably fitted into supporting sleeves 80 and 82 which on tightening, grip the inboard ends of the blades 76 and 78 and hold them at the inclination which has been set.

In this way the pitch of the propellor can be adjusted. In known manner, by inclining the blades to a greater extent, so the air blast will be increased and by feathering the blades so that they are more nearly coplanar, so the air
5. A disposable filter unit as claimed in Claim 3, in which the micro-porous material is a plastics membrane.
6. A disposable filter unit as claimed in Claim 3, 4 or 5 in which the cylindrical sheet is pleated over its entire area.
7. A disposable filter unit as claimed in Claim 6, in which said cylindrical sheet forms an outer layer of the filter element, with a correspondingly pleated activated carbon paper forming an inner layer.
8. A disposable filter unit as claimed in any one of Claims 1 to 7, in which at least a portion of the container is transparent or translucent for observing the condition of the filter element.
9. A fluid scavenging and filtration apparatus comprising a housing, a disposable first stage filter unit as claimed in any one of Claims 1 to 8 releasably mounted on the housing and arranged in series with a second stage filter unit located within the housing.
10. An apparatus as claimed in Claim 9, in which the outlet of the first stage filter unit is slidably received, in a fluid tight manner, in an inlet of the second stage filter unit, and an outlet of the second stage filter unit being in communication with a vacuum source, the arrangement being such that when the vacuum source is activated the or each non-return valve is moved from its closed position to an open position thereby permitting fluid to pass through the first and second stage filter units in series.
11. An apparatus as claimed in Claim 10, in which the vacuum source is a pump, the vacuum side of which is connected to the outlet of the second stage filter unit and the pressure side of which is connected to a third stage filter unit.
12. An apparatus as claimed in any one of Claims 9 to 11, in which the second stage filter unit includes a filter element having an outer cylindrical sheet of activated carbon and an inner cylindrical sheet of material which acts as a bacterial filter both inner and outer sheets being pleated over their entire area.
13. An Apparatus as claimed in any one of Claims 9 to 12, in which a pressure gauge is mounted on the housing to measure and indicate pressure build-up in the first and second stage filter units due to contamination.
14. An apparatus as claimed in any one of Claims 9 to 13, in which the housing is mounted for movement about a work area on a trolley.
15. An apparatus as claimed in any one of Claims 9 to 14, in which the apparatus is antistatic for use in hospital operating theatres.
16. A disposable filter unit constructed and arranged substantially as hereinbefore described with reference to and as illustrated in Figures 1 and 2 of the accompanying drawings.
17. A fluid scavenging and filtration apparatus constructed and arranged substantially as hereinbefore described, with reference to and as illustrated in, the Figures of the accompanying drawings.