NZ193050A

NZ193050A - Air blast sprayer:unitary adjustable pitch fanatomiser structure

Info

Publication number: NZ193050A
Application number: NZ193050A
Authority: NZ
Inventors: J M Mcmahon
Original assignee: Micronair Aerial
Priority date: 1979-08-29
Filing date: 1980-03-05
Publication date: 1984-07-06
Also published as: IT8024332A0; NL8004843A; GB2057299B; BR8002315A; IN152956B; AU5614780A; ES489377A0; PT71751A; PT71751B; FR2464101B1; GB2057299A; FR2464101A1; ZA801536B; ES8100116A1; AU538772B2; IT1132570B

Description

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Gcrr.p'c-te Specification Filed: 'A0, N.Z. NO.

NEW ZEALAND Patents Act, 1953 COMPLETE SPECIFICATION "SPRAYING APPARATUS." We,; MICRONAIR (AERIAL) LIMITED, a British Company of Bembridge Fort, Sandown, Isle of wight do hereby declare the invention, for which we pray-that a Patent may be granted to us , and the method by which it is to be performed, to be particularly described in end by the following statement _ 1 -followed by 1A* 3050 - 1A - "Spraying Apparatus" This invention is concerned with spraying apparatus. More particularly it relates to apparatus for distributing liquids and has application to the distribution of chemical aids to crops. 5 The application of chemical liquids to crops from aircraft by a rotary atomiser has been disclosed in New Zealand Patent Specification-No. 128025.

In the method described in that specification the blast of air produced by the 10 movement of the aircraft through the air is an essential part of the method of distribution of the chemicals being sprayed. When, however, a rotary atomiser is mounted on the ground or, for example, on a farm tractor, such a blast of air is absent. The invention sets out to provide 15 sspraying apparatus, suitable for use on the ground, which can operate in similar fashion to the above-mentioned airborne apparatus. <£>>, According to the invention there is provided i. ' \ sPraying apparatus comprising a fixed support, an axial 193050 fan rotatably mounted on the support, the fan comprising a plurality of fan blades mounted on a boss for rotational adjustment relatively thereto about radial axes -whereby the pitch of the blades may be adjusted, a rotary atomiser including a rotatable atomising element coupled to.the axial fan downstream thereof to form a unitary structure therewith, means -for .delivering fluid under pressure to the rotary atomiser, and a fixed cowl co-axial with the fan and disposed to control a blast of air generated by the fan whereby, in use, the blast of air generated by the fan passes over the rotary atomiser to disperse the droplets produced thereby.

The blades of the axial fan may be mounted in a split boss, the parts of which are separable to allow the pitch of the blades to be adjusted.

The rotary atomiser may comprise a fixed tubular spindle for receiving a liquid to be sprayed and having closure means at one end thereof, said rotatable atomising element comprising a hollow foraminous atomising cylinder rotatably and coaxially mounted on the spindle, means being provided to permit flow of liquid from the tubular spindle to the interior of the foraminous^ atomising cylinder.

The apparatus may comprise a prime mover, such as an internal combustion engine, connected to the unitary structure including the axial fan situated within the cowl and the rotatable atomising element.

The assembly of the axial fan, the cowl and the rotary atomiser forms a spraying head, and a plurality of spraying heads, together with a container to hold the 1 930 5 liquid to be sprayed, may be mounted on a farm tractor or any other type of vehicle. The tractor power take off may be used to rotate the unitary structures and also to pressurise the liquid being sprayed. The power link between the tractor power take off and the unitary structures may include an hydraulic system and a toothed belt.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which Figure 1 is a sectional side elevation of the spraying apparatus according to the invention, Figure 2 is an end view from the air .inlet end of the spraying apparatus illustrated in Figure 1, Figure 3 illustrates a farm tractor, seen from the rear, with a support boom carrying five spraying heads, Figure 4 illustrates the farm tractor with the side portions of the support boom folded upwards and four of the spraying heads turned to spray outwards, and Figure 5 is a sectional enlargement of that part of the support boom shown in the circle A in Figure 3.

Referring to Figure 3, a farm tractor 11 has a support boom 12 attached to the back thereof by means of a conventional three point pick up. Mounted on the support boom 12 are five spraying heads 13 the construction of which will be described later. The spraying heads 13 are each attached to the support boom 12 by an adjustable support 14 so that the direction in which each spraying head 13 faces may be varied.

- A - 193050 Each side portion 15 and 16 of the support boom 12 is attached to the centre portion 17 by angled hinges 18 which allow the side portions 15 and 16 to be folded upwardly as illustrated in Figure 4. When the side portions 5 15 and 16 are in the upwardly folded position some of the spraying heads 13 may be turned on their adjustable supports 14 to face outwardly and any spraying heads 13 not required may be shut off so that orchards or vineyards may be sprayed. When the side portions 15 and 16 are folded 10 upwardly the overall width of the apparatus is reduced so that its movement from one spraying site to another is simplified.

Referring to Figures 1 and 2, each spraying head 13 has a non-rotating mounting 19 which is carried by 15 a strut 20 supported by the adjustable support 14. The mounting 19 carries a fixed tubular spindle 21. The tubular spindle 21 has two anti friction bearings (not shown) which coaxially and rotatably support on the spindle a unitary structure including a cylindrical gauze liquid 20 atomising element 22 and an axial fan 23.

The axial fan 23 has five blades 24 mounted in a split boss 2 5 the parts of which are held together by bolts and nuts which may be loosened' and the parts separated to allow the pitch of the blades 24 to be adjusted. 25 The axial fan 23 rotates within the downstream end of a cowl 26 shaped aerodynamically to control the air blast generated by the axial fan 23. The cowl 26 is if' supported, concentric with the axial fan 23> "by the strut .7 V 1 930 5 and the adjustable support 14. To obtain conveniently the double curvature shape of the cowl 26 it is made of glass reinforced plastics.

Chemical fluid to be sprayed enters the fixed tubular spindle 21 through an inlet 27 at its end carried by and passing through the non-rotating mounting 19. The opposite end of the fixed tubular spindle 21 is closed by a spring loaded valve 28 which is opened by the pressure of chemical liquid to allow the liquid to emerge into the inside of the cylindrical gauze liquid atomising element 22.

The chemical liquid is carried in a container 29 (Figure 3) on the farm tractor 11. It is pumped by a standard chemical pump (not shown) to each spraying head 13 by way of flexible and rigid pipes. One of the rigid pipes 30 is shown in section in Figure 3.

The unitary structure including the cylindrical gauze element 22 and the axial fan 23 is driven by an hydraulic system. An hydraulic reservoir and hydraulic pump are mounted on the farm tractor 11, the hydraulic pump being driven from the tractor power take off.

Flexible pipes 31 and rigid pipes 32 convey the pressurised and return hydraulic fluid between the hydraulic pump and an hydraulic motor 33 attached to the non-rotating mounting 19 by a bracket 34. A toothed drive belt 35 running on sprockets interconnects the hydraulic motor 33 and the Unitary structure. The speed of the unitary structure which includes the axial fan 23 may be changed either by altering the output of the hydraulic pump or by changing 1 930 5 0 the size of the sprockets which carry the toothed drive belt 35.

Flexible pipes are included in the pipe runs of both the chemical liquid and hydraulic systems to allow the support boom 12 to be folded and the spraying heads 13 to be turned without disturbing either system.

An advantage of a spraying unit having rotary atomisation is that an even droplet spectrum is obtained even when extremely low volumes are being sprayed. This, in combination with an air blast to distribute the droplets allows concentrated chemical liquids to be spread evenly resulting in a reduction in volume applied for a given coverage. By providing for the output of the chemical liquid pump to be variable in relation to the speed of the axial fan the invention allows the volume of liquid being sprayed to be reduced without reducing the strength of the air blast.

The invention is not limited to the application of chemicals to crops. For example a free standing unit having one spraying head may be used in an enclosed space for humidification, fumigation or any other application where a fine and even droplet spectrum by spraying is required. # 193050

Claims

WHAT WE CLAIM IS:- J

1. Spraying apparatus comprising a fixed support, an axial fan rotatably mounted on the support, the fan comprising a plurality of fan blades mounted on a boss for rotational adjustment relatively thereto about radial axes whereby the pitch of the blades may be adjusted, a rotary atomiser including a rotatable atomising element coupled to the axial fan downstream thereof to form a unitary structure therewith, means for delivering fluid under pressure to the rotary atomiser, and a fixed cowl co-axial with the fan and disposed to control a blast of air generated by the fan whereby, in use, the blast of air generated by the fan passes over the rotary atomiser to disperse the droplets produced thereby.

2. Spraying apparatus according to claim 1, wherein the blades of the axial fan are mounted in a split boss, the parts of which are separable to allow the pitch of the blades to be adjusted.

3. Spraying apparatus according to claim 1 or claim 2, wherein the rotary atomiser comprises a fixed tubular spindle for receiving a liquid to be sprayed and having closure means at one end thereof, said rotatable atomising element comprising a hollow foraminous atomising cylinder rotatably and coaxially mounted on the spindle, means being provided to permit flow of liquid from the tubular spindle to the interior of the foraminous atomising cylinder. - 8 - 193050

4. Spraying apparatus according to any of claims 1 to 3, comprising means to pressurise the liquid delivered to the rotary atomiser, said pressurising means "being so arranged that the pressure of the liquid delivered to the rotary atomiser may be varied.

5. Spraying apparatus according to any of claims 1 to 4, further comprising a prime mover drivably connected to the unitary structure including the axial fan situated within the cowl and the rotatable atomising element.

6.- Spraying apparatus according to claim 5, wherein the prime mover is an internal combustion engine.

7. A vehicle having mounted thereon spraying apparatus according to any of claims 1 to 6, and also having mounted thereon a container to hold the liquid to be sprayed and means to deliver liquid from the container to the rotary atomiser.

8. A vehicle according to claim 7, having mounted thereon a plurality of said spraying apparatuses.

9. A vehicle according to claim 7 or claim 8, wherein the vehicle is an agricultural tractor having a power take off, and wherein the power take off is used to rotate the unitary structure or structures and also to pressurise the liquid being sprayed.

10. A vehicle according to claim 9, comprising a power link between the tractor power take off and the unitary structure or structures, which power link includes an hydraulic system and a toothed belt.

11. Spraying apparatus substantially as hereinbefore '•D eav described with reference to Figure 1 and Figure 2 of the accompanying drawings.

12. A vehicle having spraying apparatus mounted thereon substantially as hereinbefore described with reference to Figures 3, 4 and 5 of the accompanying drawings. MICRONAIR (AERIAL) LIMITED By Their Attorneys HENRY HUGHES LIMITED Per: Reference has been directed, in pursuance of Section 16(1) of the Patents Act 1953» to patent No.l668l6. H. BURTON Assistant Commissioner of Patents