• 한국분무공학회지
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• 제9권4호
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• pp.31-37
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• 2004

This paper presents spray and combustion characteristics of hydrocarbon fuel injected from pressure-swirl nozzles. Three commercial nozzles with orifice diameters of 0.256, 0.308 and 0.333mm and injection pressures ranging from 0.7 to 1.3 MPa were selected f9r the experiments. Spray characteristics such as breakup length. spray angle and drop size (SMD) were analyzed using photo image analyses and Malvern Panicle Size Analyzer. The drop size was measured with and without a blower at the same measuring locations. The flame length and width were measured using photo image analyses. The temperature distribution along the axial distance and the gas emission such as CO, $CO_2\;and\;NO_x$ were studied. The breakup length decreased with an increase in injection pressure for each nozzle but increased with an increase in nozzle orifice diameter. The spray angle increased and SMD decreased with an increase in injection pressure. The flame with an increased linearly with an increase in injection pressure and in nozzle orifice diameter. The flame temperature increased with an increase in injection pressure but decreased along the axial distance. The maximum temperatures occurred closer to the burner exit and flame at axial distance of 242mm from the diffuser tip. The experimental results showed that the level of CO decreased while that of $CO_2\;and\;NO_x$ increased with an increase in injection pressure and nozzle orifice diameter.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1997년도 하계 학술대회 논문집
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• pp.74-79
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• 1997

• 농업과학연구
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• 제5권1호
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• pp.29-34
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• 1978

Gun-type nozzle에 있어서 입자(粒子)의 미립화(微粒化)를 개선(改善)코저 절선속도(切線速度)를 증가(增加)하는 방법(方法)의 일환(一環)으로 Screw 중자(中子)를 제작(製作) 장치(裝置)한 Nozzle로 실내(室內)에서 분무실험(噴霧實驗)한 결과(結果) 다음과 같은 결론(結論)을 얻었다. 분무입자(噴霧粒子)의 직경(直徑)이 클수록 분무도달거리(噴霧到達距離)는 컸으며 Screw중자(中子)를 장치(裝置)하였을 때가 장치(裝置)하지 않았을 때에 비(比)하여 분무입자(噴霧粒子)의 미립화(微粒化)는 현저히 양호(良好)하였고 분무도달거리(噴霧到達距離)는 분구(噴口)가 소구경시(小口徑時)에는 거의 차이(差異)가 없었으나 분구(噴口)가 증대(增大)함에 따라서 현저히 짧아졌다. 최고(最高) 도달거리(到達距離) 지점(地點)부터 1~2m의 분무도달거리(噴霧到達距離)에 있어서는 기류부유이동(氣流浮遊移動)의 현상(現象)으로 분무입자(噴霧粒子)가 작아졌다.

• 한국농공학회지
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• 제10권1호
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• pp.1409-1412
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• 1968

Some simple devices to demonstrate important hydraulic principles are required in fluid mechanics or hydraulics classes. Those devices should be easy to make and operate with inexpensive cost. The writer has studied some simple demonstration apparatus of hydraulic principles which were made of cheap materials. An adjustable nozzle is one of them. It can be connected to an axial flow fan so as to use air flow. By operating this apparatus, pressure changes in gradually enlarged or contracted conduits could be observed.

• Journal of Biosystems Engineering
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• 제20권3호
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• pp.217-225
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• 1995

This study was conducted to find design factors of spraying device of the boom sprayer for low volume application. Four types of nozzles(standard flat nozzle, drift guard nozzle, even flat nozzle, and hollow cone nozzle) were used for the spray characteristic experiment. Spray patterns of the nozzles were distinguished by the nozzle type, spray distance, and spray direction. The flow rate was proportional to the square root of spray pressure in all nozzles. Increased nozzle height improved spray distribution at reduced pressures and/or increased spacing. Distribution tended to improve as pressure increased within the range of pressures used for fan nozzles.

• Journal of Biosystems Engineering
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• 제35권6호
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• pp.443-449
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• 2010

A machine vision-based instrument to measure a droplet size spectrum of a spray nozzle was developed and tested to evaluate its accuracy on measuring spray droplet sizes and classifying nozzle sizes. The instrument consisted of a machine vision, light emitting diode (LED) illumination and a desktop computer. The illumination and machine vision were controlled by the computer through a C++ program. The program controlled the machine vision to capture droplet images under controlled illumination, and processed the droplet images to characterize the droplet size distribution of a spray nozzle. An image processing algorithm was developed to improve the accuracy of the system by eliminating random noise and out-of-focus droplets in droplet images while measuring droplet sizes. The instrument measured sizes of the three different balls (254.0, 497.8 and $793.8\;{\mu}m$) and the measurement ranges were $241.2-273.6\;{\mu}m$, $492.9-529.6\;{\mu}m$ and $800.8-824.1\;{\mu}m$ for 254.0-, 497.84- and $793.75-\;{\mu}m$ balls, respectively. Error of the measured droplet mean was less than 3.0 %. Droplet statistics, $D_{V0.1}$, $D_{V0.5}$ and $D_{V0.9}$, of a reference nozzle set were measured, and droplet size spectra of five spray nozzles covering from very fine to extremely coarse were measured to classify spray nozzle sizes. Ninety percent of the classification results of the instrument agreed with manufacturer's classification. A comparison study was carried out between developed and commercial instruments, and measurement results of the developed instrument were within 20 % of commercial instrument results.

• 드라이브 ㆍ 컨트롤
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• 제17권4호
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• pp.1-7
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• 2020

In orchard or crop-growing environments, pesticides are sprayed using various nozzles to prevent pests and improve productivity. Nozzles currently in use are restricted for use in multi-purpose environments, thus, it is necessary to develop new nozzles. In this study, new two-phase nozzles are proposed to improve the performance of the nozzle (flow rate, spray angle, spray particle size). The performance of the two-phase nozzles are predicted through the CFD analysis and the performance of the nozzles is compared with the experiment. The experimental results showed that the proposed two-phase nozzles are available at relatively low operating pressure condition and are capable of extensive spray particle size control. Thus, the proposed nozzles are expected to be available in various orchard environments.

• Journal of Biosystems Engineering
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• 제29권1호
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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.

• 농업과학연구
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• 제11권2호
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• pp.284-294
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• 1984

동력분무기용(動力噴霧機用) 3분두(噴頭) 분공(噴孔)의 크기, 살포각도(撒布角度) 및 와실(渦室)의 간격을 변화(變化)시키면서 최대(最大) 분무유효거리(噴霧有效距離)의 구명(究明)과 살포도(撒布度)의 개선(改善)을 위(爲)한 분두배열(噴頭配列) 방법(方法)의 분석결과(分析結果)는 다음과 같다. 1. 분공(噴孔) 직경(直徑)이 커짐에 따라 분무량(噴霧量)은 증가(增加)하였고 1번구(番口)는 2차(次) 곡선(曲線)으로 II번구(番口), III번구(番口)는 1차(次) 함수관계(關係)를 나타냈다. 2. 최대(最大) 유효거리(有效距離)는 살포각도(撒布角度)가 $15^{\circ}$일때 최대(最大) 값을 나타냈고 분공(噴孔)의 크기가 3.0mm일때 약17m, 2.5mm 및 2.0mm 일때 각각 약 14m, 약 13m로 나타났다. 3. 살포도(撒布度)의 균등개선(均等改善)을 위(爲)한 분두배열(噴頭配列)(表 6참조(參照))은 I번구(番口)의 분공(噴孔)크기에 따라 다르지만 균등계수(均等係數)는 약 6%정도(程度) 개선(改善)시킬 수 있었다. 4. 살포거리(撒布距離) 6m의 최저(最低) 살포량(撒布量)을 II번구(番口)의 와실(渦室) 간격 조절(調節)로서 개선(改善)시킬 수 있었다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2005년도 하계 학술대회 논문집
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• pp.254-258
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• 2005