WO1984003643A1 - Appareil de pulverisation electrostatique - Google Patents

Appareil de pulverisation electrostatique Download PDF

Info

Publication number
WO1984003643A1
WO1984003643A1 PCT/GB1984/000089 GB8400089W WO8403643A1 WO 1984003643 A1 WO1984003643 A1 WO 1984003643A1 GB 8400089 W GB8400089 W GB 8400089W WO 8403643 A1 WO8403643 A1 WO 8403643A1
Authority
WO
WIPO (PCT)
Prior art keywords
deflector
conductive element
electrostatic
target
charged
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/GB1984/000089
Other languages
English (en)
Inventor
Ronald Alan Coffee
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Imperial Chemical Industries Ltd
Original Assignee
Imperial Chemical Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GB838308132A external-priority patent/GB8308132D0/en
Priority claimed from GB848406502A external-priority patent/GB8406502D0/en
Application filed by Imperial Chemical Industries Ltd filed Critical Imperial Chemical Industries Ltd
Priority to AU26978/84A priority Critical patent/AU2697884A/en
Publication of WO1984003643A1 publication Critical patent/WO1984003643A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01M—CATCHING, TRAPPING OR SCARING OF ANIMALS; APPARATUS FOR THE DESTRUCTION OF NOXIOUS ANIMALS OR NOXIOUS PLANTS
    • A01M7/00—Special adaptations or arrangements of liquid-spraying apparatus for purposes covered by this subclass
    • A01M7/005—Special arrangements or adaptations of the spraying or distributing parts, e.g. adaptations or mounting of the spray booms, mounting of the nozzles, protection shields
    • A01M7/0064—Protection shields
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B5/00—Electrostatic spraying apparatus; Spraying apparatus with means for charging the spray electrically; Apparatus for spraying liquids or other fluent materials by other electric means
    • B05B5/08—Plant for applying liquids or other fluent materials to objects
    • B05B5/085—Plant for applying liquids or other fluent materials to objects the plant being provided on a vehicle

Definitions

  • This invention relates to electrostatic spraying apparatus, especially to apparatus for electrostatically spraying agricultural chemicals.
  • electrostatic spraying apparatus adapted to he moved across a crop or other target and having an electrostatic sprayhead, and a deflector comprising an electrically conductive element and an element which at least partially shrouds the conductive element, the deflector being so positioned relative to the sprayhead that when the conductive element is charged to an electrical potential in the same sense as the charge applied to the sprayhead spray droplets are urged away from the deflector and towards the target, the shrouding element being formed of a material having a thickness, dielectric strength and resistivity sufficient to prevent an electrical breakdown if the deflector is contacted by an earthed object and to reduce leakage of charge from the conductive element to the earthed object whilst allowing electrical polarisation of the material by the potential applied to the conductive element.
  • the shrouding element may be made of a material which is conventionally regarded as a high voltage insulating material, such as delrin, nylon or polypropylene.
  • a high voltage insulating material such as delrin, nylon or polypropylene.
  • lower grade materials such as low grade polyvinylchloride having pigments or filling agents therein.
  • the material of the shrouding element should have a dielectric strength such that a asonable thickness, say approximately 1 cm., is sufficient to vent an electrical breakdown and a discharge between the conductive element and an earthed object contacted by the material.
  • a conductive element at a potential of approximately 40 KV low grade polyvinylchloride is satisfactory.
  • a second requirement is that the material of the shrouding element has sufficient resistivity to reduce current leakage from the conductive element to the earthed object, thus avoiding any strain on the generator providing the voltage for the conductive element, but sufficient conductivity for the material to be polarised by the voltage applied to the conductive element. This prevents any significant reduction in the magnitude of the electric field established by the potential on the conductive element.
  • the resistivity of the material may be in the range from 10 6 to 10 11 ohm cms.
  • Figure 1 is a side view of an electrostatic spraying apparatus according to the invention mounted on a tractor;
  • Figure 2 is a perspective view, partly in section, of a part of the apparatus shown in Figure 1;
  • Figure 3 is a section of part of a deflector included in the apparatus of Figures 1 and 2.
  • an electrostatic spraying apparatus is mounted at the rear of a tractor 1 which, in use, moves the apparatus over a crop 3.
  • the apparatus includes a series of electrostatic sprayheads 5 respectively disposed at spaced locations on a boom 7.
  • a deflector 9 for urging charged spray droplets towards the crop 3.
  • each sprayhead 5 includes a nozzle 11 which is connected to a tank (not shown) containing spraying liquid. Each nozzle 11 is also electrically connected to a source 13 of high electrical potential via a lead. 14. The source 13 charges the nozzles 11 to a high voltage in the range of 10 - 40 KV. Adjacent each nozzle 11 is an earthed or relatively low potential field-adjusting electrode (not shown). Each sprayhead produces a cloud 15 of charged spray droplets which are attracted to the crop 3, which is generally at earth potential. As shown in Figures 1 and 2 of the drawings, the deflectors
  • each deflector 9 extend rearwardly and downwardly from the boom 7. As shown in Figures 2 and 3, each deflector 9 includes a conductive element 19 embedded in a sheet 17 of insulating material, which serves as a shrouding element.
  • the sheet 17 is formed of two layers 21 with the conductive element 19 disposed between the layers in the form of a sandwich.
  • each deflector 9 is arcuate in section, typically forming a quadrant of a circle. At a forward end of the deflector 9 there is an upstanding mounting flange 23 which is attached to the boom 7 by bolts 25.
  • the conductive element 19 of each deflector 9 includes a series of evenly spaced, parallel arranged wires 27, each connected at its forward end to a cross-wire 29. Each cross-wire 29 is connected to the source 13 via an electrical lead 31 and the above- mentioned lead 14.
  • a typical operating voltage for the wires 27 lies in the range of 2 - 40 KV and has the same polarity as the polarity of the charged spray droplets.
  • the tractor 1 is driven over a field so that the boom 7 carrying the sprayheads 5 and deflectors 9 passes over the crop 3, as shown in Figure 1 of the drawings.
  • Each nozzle 11 is supplied with liquid from the tank and with a high electrical potential from the source 13.
  • each deflector 9 is connected to a high electrical potential of the same polarity as the charge on the spray droplets.
  • the potential difference between each deflector 9 and the crop 3, which is generally at earth potential, produces an electrostatic field having lines of force which emerge from a deflector in a direction generally perpendicular to the surface thereof and which enter the crop in a direction generally perpendicular to the ground.
  • the effect of the electrostatic field is therefore to repel charged spray droplets away from the deflectors 9 and towards the crop 3.
  • the wires 27 of the conductive element 19 are completely shrouded by the sheet 17 of insulating material, the wires do not come into contact with the crop 3 or with other external objects which would tend to earth the wires and cause excessive leakage of charge. A very modest power source is thus sufficient to maintain the conductive element 19 at a high potential. Moreover, the presence of the sheet 17 prevents an operator touching the element 19 and receiving an electrical shock, and it also prevents charge leakage when the apparatus is operated in wet conditions.
  • the deflectors 9 produce a downdraft of air which further increases the penetration of spray into the crop. This is especially beneficial when it is desired to treat the lower regions of a crop against, say, fungal spores.
  • the deflectors 9 may also be inclined to the direction of forward movement so as to produce a sideways movement of air. Operating variables such as dimensions, shapes and air speeds will naturally depend upon a variety of factors such as the structural characteristics of the materials used, the crops being sprayed and the capacity of the vehicle on which the apparatus is mounted.
  • the deflectors may extend a horizontal distance of 0.4 metres behind the sprayheads.
  • Each deflector curves downwards towards the target crop, and depending upon the desired level of penetration may terminate above, at or below crop height (with narrow-leaf crops such as cereals or broad- leaf crops such as soya).
  • the forward ends of the deflectors would normally be attached to the boom a few centimetres above the nozzles.
  • the wires 27 are copper and the layers 21 of the sheet 17 are made of delrin.
  • delrin it is possible to use some other material which is not degraded by exposure to sunlight or chemical solvents, for example nylon.
  • the series of parallel wires 27 can be replaced by a network of wires or by a metal sheet or foil.
  • the sheet 17 can be formed of a single layer having the conductive element moulded therein.
  • the deflectors 9 may extend rearwardly and horizontally rather than rearwardly and downwardly from the boom 7. Instead of the series of deflectors 9 there may be a single deflector which extends over the full length of the boom. In this case, it may be necessary to provide one or more ground engaging wheels for supporting a rear end of the deflector.
  • the conductive element need not be embedded in the insulating material, it being sufficient in some instances to arrange the insulating material so as to shroud the element sufficient to prevent contact with the crop.
  • the deflectors 9 can also be charged by means of a pointed electrode in the vicinity of the nozzle, say, directed at the deflector and maintained at a high potential. The electrode produces a corona discharge which rapidly charges the deflector by ion bombardment.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Insects & Arthropods (AREA)
  • Pest Control & Pesticides (AREA)
  • Wood Science & Technology (AREA)
  • Zoology (AREA)
  • Environmental Sciences (AREA)
  • Electrostatic Spraying Apparatus (AREA)
  • Catching Or Destruction (AREA)

Abstract

Appareil de pulvérisation électrostatique possédant une tête de pulvérisation électrostatique (5) et un déflecteur (9) comportant un élément électriquement conducteur (19) enveloppé au moins partiellement par un matériau électriquement isolant (17). L'élément conducteur (19) est chargé à un potentiel électrique du même signe que la charge appliquée à la tête de pulvérisation et le déflecteur (9) est positionné de telle façon que des gouttelettes de pulvérisation chargées (15) sont écartées du déflecteur pour être dirigées vers la culture (3). La perte de charge de l'élément conducteur est réduite grâce à la présence du matériau isolant.
PCT/GB1984/000089 1983-03-21 1984-03-19 Appareil de pulverisation electrostatique Ceased WO1984003643A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU26978/84A AU2697884A (en) 1983-03-21 1984-03-19 Electrostatic spraying apparatus

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB838308132A GB8308132D0 (en) 1983-03-24 1983-03-24 Electrostatic spraying apparatus
GB848406502A GB8406502D0 (en) 1984-03-13 1984-03-13 Electrostatic spraying apparatus

Publications (1)

Publication Number Publication Date
WO1984003643A1 true WO1984003643A1 (fr) 1984-09-27

Family

ID=26285602

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1984/000089 Ceased WO1984003643A1 (fr) 1983-03-21 1984-03-19 Appareil de pulverisation electrostatique

Country Status (3)

Country Link
EP (1) EP0145723A1 (fr)
CA (1) CA1217935A (fr)
WO (1) WO1984003643A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108739770A (zh) * 2018-08-01 2018-11-06 山东省农药科学研究院 一种电场偏转式省药静电喷雾装置及其使用方法
CN111011332A (zh) * 2019-11-04 2020-04-17 东北大学 一种机载式果园农药喷雾装置及使用方法
CN115413645A (zh) * 2022-09-28 2022-12-02 舒城县农业科学研究所 一种水稻育秧用农药喷洒装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE960526C (de) * 1952-01-17 1957-03-21 Siemens Ag Einrichtung zur elektrostatischen Oberflaechenbehandlung von nicht oder schlecht leitenden Werkstuecken
FR2370525A1 (fr) * 1976-11-10 1978-06-09 Onoda Cement Co Ltd Procede et appareil pour appliquer electrostatiquement des revetements de poudre
AU506398B3 (en) * 1978-10-06 1979-12-20 Australian Agricultural Machinery Pty. Ltd. Agricultural spray
GB2092478A (en) * 1981-02-09 1982-08-18 Ici Plc Electrostatic spraying process and apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE960526C (de) * 1952-01-17 1957-03-21 Siemens Ag Einrichtung zur elektrostatischen Oberflaechenbehandlung von nicht oder schlecht leitenden Werkstuecken
FR2370525A1 (fr) * 1976-11-10 1978-06-09 Onoda Cement Co Ltd Procede et appareil pour appliquer electrostatiquement des revetements de poudre
AU506398B3 (en) * 1978-10-06 1979-12-20 Australian Agricultural Machinery Pty. Ltd. Agricultural spray
GB2092478A (en) * 1981-02-09 1982-08-18 Ici Plc Electrostatic spraying process and apparatus

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108739770A (zh) * 2018-08-01 2018-11-06 山东省农药科学研究院 一种电场偏转式省药静电喷雾装置及其使用方法
CN111011332A (zh) * 2019-11-04 2020-04-17 东北大学 一种机载式果园农药喷雾装置及使用方法
CN111011332B (zh) * 2019-11-04 2022-02-01 东北大学 一种机载式果园农药喷雾装置及使用方法
CN115413645A (zh) * 2022-09-28 2022-12-02 舒城县农业科学研究所 一种水稻育秧用农药喷洒装置
CN115413645B (zh) * 2022-09-28 2023-12-15 舒城县农业科学研究所 一种水稻育秧用农药喷洒装置

Also Published As

Publication number Publication date
CA1217935A (fr) 1987-02-17
EP0145723A1 (fr) 1985-06-26

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