• Journal of Biosystems Engineering
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• v.24 no.5
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• pp.391-398
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• 1999

The spraying status of the electrostatic sprayer was evaluated by processing surface spraying images of the natural leaves. Water solution of the fluorescent material was used as a spray medium. The image of the lights reflected by fluorescent droplets was captured under UV light using a color CCD camera. Coverage rate, particle density, and the size distribution of particles were analyzed from the surface images of leaves under various spraying conditions such as spraying nozzle angle and object distance. Spraying characteristics of the electrostatic sprayer was evaluated in comparison with the conventional one. In a case of electrostatic sprayer, coverage rate and particle density increased by the average of 1.57times and 1.01times respectively under various nozzle angles and distances. The number of particle under the diameter of 50 ${\mu}{\textrm}{m}$ also increased significantly.

• Journal of Biosystems Engineering
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• v.29 no.1
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• pp.21-28
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• 2004

Spraying is one of the most efficient methods for pesticide and insecticide control. Generally, orchard sprayers(aircarrier sprayer) are used for such applications. However, when an orchard sprayer is used, only 20% of total amount of spray deposits on the target. The rest of spray are not only wasted but are also potential sources of environmental pollution. The research far the development of electrostatic spraying system for orchard sprayer was conducted to develop the new pesticide application technology for the reduction of environmental pollution and f3r the production of safe agricultural products. The spray characteristics for nozzles with the different charging methods were tested and the effect of electrostatic charge was analyzed, in the laboratory experiments. The results of this study indicate that the capacitive type of electrostatic spraying nozzle exhibits a large current deposition of water sprays on the sample target. The covering area ratio by conventional spraying system was 10.2%, while that of electrostatic sprays with pulse induction charging method gave the increased covering area ratio by 4.3 times.

• Agricultural and Biosystems Engineering
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• v.3 no.1
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• pp.29-34
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• 2002

Two charging methods of electrostatic nozzle, i.e. induction and ionized field corona charging, were designed and evaluated for orchard sprayer application. An artificial (metallic) target was constructed and used in this experiment. The charge-to-mass ratio for the induction electrode was measured by using the Faraday cage. Two conventional pressure-swirl nozzles have been employed with different orifice diameters under the same experimental operating conditions. A commercial pressure-swirl nozzle with orifice diameter of 1.0 was used for the conventional spray. The diameter of the electrostatic was 0.59 mm. The experiment was carried out for individual nozzle sprays at $0^{\circ}$, $20^{\circ}$ and $50^{\circ}$ oriented angles and three nozzles, sprayed simultaneously at a distance of 1.0 and 2.0 m from the nozzle tip to the target. The nozzles were mounted on a carriage with constant speed of 1.26 km/h with a blower attached. The weighing method was employed to evaluate for the spray deposition, ground loss and estimated drift. The results show more promising for the induction charging method, especially at $20^{\circ}$oriented angle at a distance of 1.0 m from the target for a single nozzle and when all three nozzles were operated simultaneously for spray deposition. The results of the induction charging method show promising with the developed electrostatic technique.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.811-818
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• 2000

Agricultural chemicals spraying is one of the most efficient methods for pesticides control. General farming groups use Speed Sprayer but its deposition amount on practical crops is only 20% of total amount in SS case. Agricultural chemicals which fail to arrive the crops not only cause environmental contamination but loss of agriculture chemicals by lower deposition efficiency. For the purpose of improvement of these problems, this experiment proposes SS attachment type electrostatic induction spraying apparatus with DC power which improves deposition efficiency of agriculture chemicals on the crops.

• Journal of Biosystems Engineering
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• v.21 no.4
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• pp.456-466
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• 1996

Electrostatic spraying is needed for today's sustainable farming. An electrostatic spraying nozzle was developed and its spraying performance was evaluated. High voltages of 15㎸, 20㎸, and 25㎸ were supplied for the electrostatic electrode. Artificial and real apple targets were used for the spraying experiments. Insulated material was used around the electrode to protect the loss of electrostatic effect. Three angles (0, 45, 90 degree) of spraying direction were used for the spraying test. The performance of electrostatic spraying was improved from 204.5% upto 429.2% on the apple targets.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.02a
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• pp.88-94
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• 2000

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.11 no.2
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• pp.237-240
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• 2006

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.12
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• pp.573-578
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• 2003

In this study, new type of induction charging system for electrostatic spraying was manufactured and proposed to improve the electrical safety and charging efficiency. And parameters of proposed system to generate the maximum deposition current with electrical safety were selected and investigated. The selected parameters were frequency of square pulse and thickness of insulation material, outer diameter of device and thickness and positions of electrode. Charging quantity of water drop was measured by deposition current detected from sensing plate indirectly. The maximum deposition current for each parameter were 3.5[uA] at the frequency of 15[kHz] and thickness of 0.25[mm] insulating layer. And maximum deposition currents were 2.8[uA] and 3.0[uA] at 25[mm] outer diameter of charging device and 0.25[mm] thickness of electrode each. Effects of electrode position from spraying nozzle on deposition current was a little.

• Agricultural and Biosystems Engineering
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• v.3 no.1
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• pp.44-54
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• 2002

A brief review of current status in the field of agricultural spray and future research challenges are presented. Researches on the pesticides sprays, pollen sprays, postharvest sprays, and biological control agent sprays among the various applications of agricultural spray were selected and reviewed. In the agrochemical sprays, the techniques to increase the deposition such as electrospray and reduce the drift such as introductions of drift retardants and of mechanical means are reviewed. The introduction of mechanical means includes low drift, air-assisted, air inclusion, shield or shroud assisted and pulse flow nozzles. For flat fan nozzles, the data of breakup length and thickness of liquid sheet are essential to understand the atomization processes and develop the transport model to target In the air-assisted spray technology to reduce drift, further works on the effect of application height on drift and air assistance on droplet size should be followed. In addition, methods for quantifying the included air in the air inclusion techniques are required. The atomization characteristics of biopesticides spray are not being elucidated and the formulations of biopesticides should be taken into account the spray characteristics of existing nozzle and sprayer. A few researches on the droplet size of fallout can be found in the literature. A combined technology with electrostatic method into one of method for the reduction of drift may be an effective strategy for increasing deposition and reducing drift. Only an integrated approach involving all stakeholders such as engineers, chemists, and biologists, etc. can result in improved application of agricultural spray.