Design and Evaluation of a Novel Efficient Air-Assisted Hollow-Cone Electrostatic Nozzle

For crop protection, electrostatic spraying technology significantly improves deposition uniformity and pesticide utilization through the “wraparound-adsorption” effect of charged droplets. However, existing electrostatic nozzles using hydraulic atomization suffer from low charge-to-mass ratios due...

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Main Authors: Li Zhang, Zhi Li, Huaxing Chu, Qiaolin Chen, Yang Li, Xinghua Liu
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Agriculture
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Online Access:https://www.mdpi.com/2077-0472/15/12/1293
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author Li Zhang
Zhi Li
Huaxing Chu
Qiaolin Chen
Yang Li
Xinghua Liu
author_facet Li Zhang
Zhi Li
Huaxing Chu
Qiaolin Chen
Yang Li
Xinghua Liu
author_sort Li Zhang
collection DOAJ
description For crop protection, electrostatic spraying technology significantly improves deposition uniformity and pesticide utilization through the “wraparound-adsorption” effect of charged droplets. However, existing electrostatic nozzles using hydraulic atomization suffer from low charge-to-mass ratios due to unclear principles for optimizing electrode parameters. To this end, this study designs and evaluates a novel air-assisted hydraulic-atomization hollow-cone electrostatic nozzle. First, the air-assisted hollow-cone nozzle was designed. High-speed imaging was then employed to obtain morphological parameters of the liquid film (length: 2.14 mm; width: 1.96 mm; and spray angle: 49.25°). Based on these parameters, an electric field simulation model of the electrostatic nozzle was established to analyze the influence of electrode parameters on the charging performance and identify the optimal parameter combination. Finally, feasibility and efficiency evaluation experiments were conducted on the designed electrostatic nozzle. The experimental results demonstrate that cross-sectional dimensions of the electrode exhibit a positive correlation with the surface charge density of the pesticide liquid film. In addition, optimal charging performance is obtained when the electrode plane coincides with the tangent plane of the liquid film leading edge. Based on these charging laws, the optimal electrode parameters were determined as follows: 2.0 × 2.0 mm cross-section with an electrode-to-nozzle tip distance of 3.8 mm. With these parameters, the nozzle achieved a droplet charge-to-mass ratio of 4.9 mC/kg at a charging voltage of 3.0 kV. These charged droplets achieved deposition coverages of 12.19%, 5.72%, and 5.91% on abaxial leaf surfaces in the upper, middle, and lower soybean canopies, respectively, which is a significant improvement in deposition uniformity. This study designed a novel air-assisted hollow-cone electrostatic nozzle, elucidated the optimization principles for annular induction electrodes, and achieved improved spraying performance. The findings contribute to enhanced pesticide application efficiency in crops, providing valuable theoretical guidance and technical references for electrostatic nozzle design and application.
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language English
publishDate 2025-06-01
publisher MDPI AG
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series Agriculture
spelling doaj-art-34e173b9bd5e49cf84d5edafdbee4cb62025-08-20T02:23:59ZengMDPI AGAgriculture2077-04722025-06-011512129310.3390/agriculture15121293Design and Evaluation of a Novel Efficient Air-Assisted Hollow-Cone Electrostatic NozzleLi Zhang0Zhi Li1Huaxing Chu2Qiaolin Chen3Yang Li4Xinghua Liu5College of Resources, Shandong University of Science and Technology, Tai’an 271019, ChinaCollege of Mechanical & Electronic Engineering, Shandong Agricultural University, Tai’an 271018, ChinaCollege of Mechanical & Electronic Engineering, Shandong Agricultural University, Tai’an 271018, ChinaCollege of Mechanical & Electronic Engineering, Shandong Agricultural University, Tai’an 271018, ChinaCollege of Mechanical & Electronic Engineering, Shandong Agricultural University, Tai’an 271018, ChinaCollege of Mechanical & Electronic Engineering, Shandong Agricultural University, Tai’an 271018, ChinaFor crop protection, electrostatic spraying technology significantly improves deposition uniformity and pesticide utilization through the “wraparound-adsorption” effect of charged droplets. However, existing electrostatic nozzles using hydraulic atomization suffer from low charge-to-mass ratios due to unclear principles for optimizing electrode parameters. To this end, this study designs and evaluates a novel air-assisted hydraulic-atomization hollow-cone electrostatic nozzle. First, the air-assisted hollow-cone nozzle was designed. High-speed imaging was then employed to obtain morphological parameters of the liquid film (length: 2.14 mm; width: 1.96 mm; and spray angle: 49.25°). Based on these parameters, an electric field simulation model of the electrostatic nozzle was established to analyze the influence of electrode parameters on the charging performance and identify the optimal parameter combination. Finally, feasibility and efficiency evaluation experiments were conducted on the designed electrostatic nozzle. The experimental results demonstrate that cross-sectional dimensions of the electrode exhibit a positive correlation with the surface charge density of the pesticide liquid film. In addition, optimal charging performance is obtained when the electrode plane coincides with the tangent plane of the liquid film leading edge. Based on these charging laws, the optimal electrode parameters were determined as follows: 2.0 × 2.0 mm cross-section with an electrode-to-nozzle tip distance of 3.8 mm. With these parameters, the nozzle achieved a droplet charge-to-mass ratio of 4.9 mC/kg at a charging voltage of 3.0 kV. These charged droplets achieved deposition coverages of 12.19%, 5.72%, and 5.91% on abaxial leaf surfaces in the upper, middle, and lower soybean canopies, respectively, which is a significant improvement in deposition uniformity. This study designed a novel air-assisted hollow-cone electrostatic nozzle, elucidated the optimization principles for annular induction electrodes, and achieved improved spraying performance. The findings contribute to enhanced pesticide application efficiency in crops, providing valuable theoretical guidance and technical references for electrostatic nozzle design and application.https://www.mdpi.com/2077-0472/15/12/1293electrostatic sprayinghollow-cone nozzleconductive liquid filmparameter optimizationcharge-to-mass ratio
spellingShingle Li Zhang
Zhi Li
Huaxing Chu
Qiaolin Chen
Yang Li
Xinghua Liu
Design and Evaluation of a Novel Efficient Air-Assisted Hollow-Cone Electrostatic Nozzle
Agriculture
electrostatic spraying
hollow-cone nozzle
conductive liquid film
parameter optimization
charge-to-mass ratio
title Design and Evaluation of a Novel Efficient Air-Assisted Hollow-Cone Electrostatic Nozzle
title_full Design and Evaluation of a Novel Efficient Air-Assisted Hollow-Cone Electrostatic Nozzle
title_fullStr Design and Evaluation of a Novel Efficient Air-Assisted Hollow-Cone Electrostatic Nozzle
title_full_unstemmed Design and Evaluation of a Novel Efficient Air-Assisted Hollow-Cone Electrostatic Nozzle
title_short Design and Evaluation of a Novel Efficient Air-Assisted Hollow-Cone Electrostatic Nozzle
title_sort design and evaluation of a novel efficient air assisted hollow cone electrostatic nozzle
topic electrostatic spraying
hollow-cone nozzle
conductive liquid film
parameter optimization
charge-to-mass ratio
url https://www.mdpi.com/2077-0472/15/12/1293
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AT qiaolinchen designandevaluationofanovelefficientairassistedhollowconeelectrostaticnozzle
AT yangli designandevaluationofanovelefficientairassistedhollowconeelectrostaticnozzle
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