• Title/Summary/Keyword: spraying

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Spraying Performance Evaluation of Spraying Nozzle Using Electrostatic Effect (정전효과를 이용한 분무노즐의 분무성능 평가)

  • 조성인;이동훈
    • 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.

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Spray Coating Technology (스프레이 코팅 기술)

  • Lee, Chang-Hee
    • Journal of ILASS-Korea
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    • v.13 no.4
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    • pp.193-199
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    • 2008
  • Spray coating is a versatile surface modification technology in which coating is built-up based on the successive deposition of micron-scaled particles. Depending on the coating materials, the coatings can meet the required mechanical properties, corrosion resistance, and other properties of base materials. Spraying processes are mainly classified into thermal and kinetic spraying according to their bonding mechanism and deposition characteristics. Specifically, thermal spraying process can be further classified into many categories based on the design and mechanism of the process, such as frame spraying, arc spraying, atmospheric plasma spraying (APS), and high velocity oxygen-fuel (HVOF) spraying, etc. Kinetic spraying or cold gas dynamic spraying is a newly emerging coating technique which is low-temperature and high-pressure coating process. In this paper, overall view of thermal and kinetic spray coating technologies is discussed in terms of fundamentals and industrial applications. The technological characteristics and bonding mechanism of each process are introduced. Deposition behavior and properties of technologically remarkable materials are reviewed. Furthermore, industrial applications of spray coating technology and its potentials are prospected.

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Development of Swirl Disc Nozzles for Knapsack Sprayers (배부식 방제기를 위한 디스크형 노즐 개발)

  • Gwak H.H.;Kim Y.J.;Rhee J.Y.
    • Journal of Biosystems Engineering
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    • v.31 no.3 s.116
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    • pp.153-160
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    • 2006
  • This study was performed to evaluate some geometrical characteristics of disc type swirl nozzles and to develop nozzles having improved spraying performance for knapsack sprayers. Considered geometrical characteristics of the nozzles were disc thickness, orifice diameter, swirl chamber diameter and shape of the swirl chamber (nozzle chamber). 3 types of nozzle cores were compared. Main results of this study were as follows. 1. Spraying angle (A) was increased with decreasing disc thickness (x), and with increasing orifice diameter (y) or spraying pressure (z). The equation was as a follow. $$A=3.95\frac{1}{x}+73.50\sqrt{y}+18.97\sqrt{z}-60.16$$ 2. Spraying flow rate (F) was increased with decreasing disc thickness (x), and with increasing orifice diameter (y) or spraying pressure (z). The equation was as a follow. $$F=-89.95x+611.09y+620.49\sqrt{z}-868.20$$ 3. Mean spraying droplet size (V) was decreased with decreasing disc thickness (x), with increasing orifice diameter (y) in low spraying pressure, with decreasing orifice diameter (y) in high spraying pressure, and with increasing spraying pressure (z). $$V=148.77x^4-746.85x^3+1311.76x^2-917.31x$$ 4. The spray pattern was compared using CV values. The CV value of the nozzle core type 1 was 26.7% in spraying pressure $3\;kgf/cm^2$, the CV value of the core type 2 was 23.6% in spraying pressure $2\;kgf/cm^2$, the CV value of the core type 3 was 20.6% in spraying pressure $1\;kgf/cm^2$. 5. Minimum spraying pressure was improved from $1.5\;kgf/cm^2\;to\;1.0\;kgf/cm^2$ by changes of nozzle core shape.

THE EFFECT OF SPRAYING PARAMETEES ON THE PROPERTIES OF HYDROXYAPATITE COATUNG

  • Park, K.S.;Huh, W.T.;Son, Y.H.;Kim, C.K.;Kim, S.Y.;Kim, S.G.;Kim, S.W.
    • Journal of the Korean institute of surface engineering
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    • v.29 no.6
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    • pp.695-702
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    • 1996
  • Plasma spraying process was employed to produce HA coating on Ti6A14V alloy for the development of a dental implant. The goal of this research was to find optimum spraying conditions for HA coating on Ti6Al4V. This study was thus designed carefully to evaluate how spraying parameters affect various physical properties of a HA coating layer, such as phase composition and bond strength. In plasma spraying, spraying parameters such as hydrogen flow rates and spraying distances were varied systematically to change the degree of the melting of starting HA powder in plasma jet. It was revealed that the deposition efficiency increased with increasing a hydrogen flow rate, and the bond strength between the HA-coated layer and Ti-alloy substrate increased with hydrogen flow rate, but decreased with spraying distance. Therefore, the hydrogen flow rate and the spraying distance should be carefully controlled to obtain the reasonable bond strength simultaneously.

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Effects of Spraying Conditions on the Mechanical Properties of Titania Ceramic Coating Layer (티타니아 세라믹 熔射皮膜의 機械的 特性에 미치는 熔射條件의 影響에 관한 硏究)

  • Kim, Yeong-Sik;Kim, Yeong-Sik
    • Journal of Advanced Marine Engineering and Technology
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    • v.15 no.3
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    • pp.39-44
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    • 1991
  • The purpose of this investigation is to examine the effects of spraying conditions on the mechanical properties of flame-sprayed titania ceramic coating layer. Titania ceramic was sprayed onto the mild steel substrate under the various spraying conditions. Spraying distances were 100, 150, 200, 250mm respectively and pinch air pressures were 0.2 0.3, 0.4 MPa at each spraying distance. The mechanical properties such as microhardness, adhesive strength and erosion wear resistance were tested for the specimens sprayed under the various spraying conditions above mentioned. The optimum operational conditions obtained through the experimental results were 150mm of spraying distance and 0.3 MPa of pinch air pressure.

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Development of Control System of Twin-Fluid Nozzles for Controlling Spraying Rate and Droplet Size (이류체노즐을 이용한 분무량과 분무입경 제어시스템 개발)

  • 이중용;안형철;정창주
    • Journal of Biosystems Engineering
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    • v.25 no.1
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    • pp.11-18
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    • 2000
  • In precision chemical application increment of biological efficacy with less chemical is the virtue. spraying rate and droplet size is closely related to biological efficacy. this study was performed to develope a spray-control-system that could control spraying rate and droplet size independently. Twin-fluid nozzles were selected and tested to certify if the nozzles were suitable for the objective of this study. Characteritics of the nozzles i.e., spraying rte and droplet size change u8nder the changes of spraying pressure and air pressure were statistically modeled. The model had I to 1 matching property between dependent variables and independent variables. Using the property and the model, inverse relationship could be determined between variables. A feedback spray control system was developed and tested with predetermined error of 5 % in pressure. The system showed 4 % error in spraying rate and 9 % error in droplets size. Performance of the system could be upgraded by fine tuning but, in practical sense keeping air pressure in the field sprayer was the bottle neck of commercialization of the spray system.

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A prediction of mold temperature distribution and lifetime with different spray process of mold release agent in high pressure diecasting mold using computer simulation (컴퓨터 시뮬레이션을 이용한 고압다이캐스팅 금형의 이형제 분사공정에 따른 금형온도분포 및 금형수명 예측)

  • Kim, Dong-Hyun;Yoon, Sang-Il;Chang, Dae-Jung
    • Design & Manufacturing
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    • v.13 no.2
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    • pp.49-53
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    • 2019
  • The temperature distribution and lifetime of molds were predicted by computer simulation analysis with various spraying and blowing process of high pressure die casting. After varying the spraying angle and time, the mold temperature, heat exchange and mold life were predicted. As the spraying angle increases, the maximum temperature of the mold decreases, which is because the spraying area increases and the heat exchange with the mold increases. Heat exchange occurs more actively in the blowing process than in the spraying process. This is because the cooling is not performed due to the steam generation. When the spraying angle is 50 degree, the minimum life of the mold is analyzed 200 times. After adjusting the blowing time from 5s to 3s, the minimum lifetime of the mold has been increased almost twice.

Predicting the spray uniformity of pest control drone using multi-layer perceptron (다층신경망을 이용한 드론 방제의 살포 균일도 예측)

  • Baek-gyeom Seong;Seung-woo Kang;Soo-hyun Cho;Xiongzhe Han;Seung-hwa Yu;Chun-gu Lee;Yeongho Kang;Dae-hyun Lee
    • Journal of Drive and Control
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    • v.20 no.3
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    • pp.25-34
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    • 2023
  • In this study, we conducted a research on optimizing the spraying performance of agricultural drones and predicted the spraying performance in various flight conditions using the multi-layer perceptron (MLP). Data was collected using a test device for pesticide spraying performance according to the water sensitive paper (WSP) evaluation. MLP training involved supervised learning to achieve a coefficient of variation (CV), which indicates the degree of uniform spraying. The performance evaluation was conducted using R-squared (R2), the test samples showed an R2 of 0.80. The results of this study showed that drone spraying performance can be predicted under various flight environments. In addition, the correlation analysis between flight conditions and predicted spraying performance will be useful for further research on optimizing the spraying performance of agricultural drones.

An Experimental Study on the Spray Characteristics by Twin-Fluid Atomizer for Wide Band Spray (광폭면 분무를 위한 2유체 노즐의 분무 특성에 관한 연구)

  • Lee, Joong-Soon
    • Journal of ILASS-Korea
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    • v.13 no.4
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    • pp.212-219
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    • 2008
  • To develop the twin-fluid atomizer having the excellent performance of painting, the spray characteristics of how a wide area can be painted efficiently by one time spraying were studied in this paper. Spray phenomena are affected by the many factors determining the spray field such as the spraying pressure of gas, the spraying pressure and viscosity of liquid paints, the opening duration of needle valve, the design dimension of nozzle, and so on. As the results of experiments, these factors affecting on spray characteristics were suggested as followings; 1) The optimum spraying pressure of gas was $0.015{\sim}0.02\;kPa$, and the appropriate spraying pressure of liquid paint was 0.01kPa, In these situations, the setting up pressures must be compensated as much as the losing amount of pressure because a decompression occurred when operating valves. 2) The duration of opening the needle valve must be sustained for $1{\sim}2$ seconds to inject gas after spraying the liquid paint. This operating of the needle valve was necessary to avoid the affect on the changing of liquid column length, and to prevent the droplet deposit at the initial time of spraying. 3) The spray tip penetration was gained form the experimental equation, and the effective spraying angle was $85^{\circ}{\pm}5^{\circ}$ just at he appropriate spraying pressure of gas. The distribution of the area sprayed had the variation in $350{\pm}50\;mm$ because of the spraying pressure of gas, the its distance from the spray tip, and the lift of the needle valve.

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Spraying Status Evaluation of the Electro-static Sprayer Using Computer Image Processing (컴퓨터 영상처리를 이용한 정전분무기의 분무상태 평가)

  • Hwang, H.;Cho, S. I.;Cho, D. Y.
    • 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.

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