CAJ | 학술논문

农药雾滴粒径是影响农药在靶标上的沉积量和分布均匀性的主要因素，测试方法和仪器很多。该文使用激光粒子图像分析测试系统（particle/droplet image analysis，PDIA）、Sympatec HELOS Vario激光衍射粒度分析仪和Spraytec实时喷雾粒度分析仪3种常用的雾滴粒径分析仪对ST喷头进行雾滴粒径测试，结果表明3种仪器测得的雾滴体积中径（VMD，volume median diameter）绝对结果有差异，但是与已有的喷头雾滴细度界限值相比，该文所用的不同仪器测量结果对相同喷头的定级相同。鉴于此，选用Spraytec对Lechler公司生产的IDK、TR和ST 3种类型、2个国标流量代号（02和03）的6种型号喷头在喷雾扇面内的VMD进行测试，基于最小二乘法对测试结果进一步分析拟合，得到VMD在喷雾扇面内分布规律的函数形式。回归拟合函数以位置信息（喷雾高度，水平位置）为自变量、VMD为因变量，经回归效果检验可知各函数F统计量皆大于其F临界值（α=0.05），且相关指数都大于0.8，表明该文中所得的拟合函数可以较准确地描述雾滴粒径分布规律，并较精确地预测出扇面中非测试点的雾滴粒径。这些拟合函数为进一步研究喷杆各喷头喷雾扇面叠合后的雾滴粒径分布提供了基础。
농약무적립경시영향농약재파표상적침적량화분포균균성적주요인소，측시방법화의기흔다。해문사용격광입자도상분석측시계통（particle/droplet image analysis，PDIA）、Sympatec HELOS Vario격광연사립도분석의화Spraytec실시분무립도분석의3충상용적무적립경분석의대ST분두진행무적립경측시，결과표명3충의기측득적무적체적중경（VMD，volume median diameter）절대결과유차이，단시여이유적분두무적세도계한치상비，해문소용적불동의기측량결과대상동분두적정급상동。감우차，선용Spraytec대Lechler공사생산적IDK、TR화ST 3충류형、2개국표류량대호（02화03）적6충형호분두재분무선면내적VMD진행측시，기우최소이승법대측시결과진일보분석의합，득도VMD재분무선면내분포규률적함수형식。회귀의합함수이위치신식（분무고도，수평위치）위자변량、VMD위인변량，경회귀효과검험가지각함수F통계량개대우기F림계치（α=0.05），차상관지수도대우0.8，표명해문중소득적의합함수가이교준학지묘술무적립경분포규률，병교정학지예측출선면중비측시점적무적립경。저사의합함수위진일보연구분간각분두분무선면첩합후적무적립경분포제공료기출。
In order to investigate the function expression of droplet size distribution in the spray sheet for agricultural nozzles to improve the pesticide efficacy, some common nozzle types were tested in this study. At present many methods and equipment were used for measuring droplet size. Droplet size is a main parameter influencing the deposition rate and distribution uniformity of pesticide on the target. However, different test results may be caused by different methods or equipment. For selecting a suitable analyzer to test droplet size distribution, three common droplet size analyzers were applied to measure droplet sizes of ST110-03 and ST110-02 nozzles which were standard flat-fan nozzles manufactured by Lechler GmbH. The three analyzers were Particle/Droplet image analysis system, Sympatec HELOS Vario particle size analyzer and Spraytec laser diffraction system and were referred to as PDIA, Sympatec and Spraytec, respectively. Their respective locations were the Institute for Application Techniques in Plant Protection of JKI (Julius Kühn-Institut), Germany, the Centre for Pesticide Application and Safety of the University of Queensland, Australia, and the Centre for Chemicals Application Technology of China Agricultural University, China. For all the sprays in this study, tap water was sprayed at an operating pressure of 0.3 MPa, and each apparatus was operated complying with its corresponding experimental procedure. For each nozzle type, 3 nozzles were tested with three replications. Results showed that absolute results differed between different tests depending on measuring protocol and type of measuring apparatus, but the nozzle classifications were the same, comparing the results with limits of BCPC nozzle classification obtained by PDIA in JKI. Spraytec was more accessible to authors than other analyzers; therefore, it was selected to study the distribution of droplet size. The volume median diameters (VMDs) of air-induction compact nozzles (IDK), standard flat-fan nozzles (ST) and hollow-cone nozzles (TR), with the orifice sizes of 02 and 03 for each type, were measured at different positions in the spray sheet. The nozzles were all produced by Lechler GmbH in Germany. It was found that the VMD distributions were symmetric for all tested nozzles and the axis of symmetry was the centerline of spray sheet. The VMDs of IDK nozzles were significantly larger than other two types’. The coefficient of variation (CV) of droplet sizes, which were tested at different spray heights but the same horizontal position, indicated that the VMDs of IDK nozzles varied with spray height obviously. Meanwhile, at a fixed spray height, the VMD distribution of IDK along the horizontal direction appeared to be W-shaped; the distributions of ST and TR were parabolas. The parabola opening of ST was larger than that of TR. The tested VMD was then fitted with program code using Matlab software based on least square method. In the fitted VMD distribution equation, independent variables were spray height and horizontal position and dependent variable was VMD. The significant relationship between distribution position and VMD was found, the significance thresholdα was set at 0.05. Results also showed that theF-statistic calculated from the data of each nozzle was greater than the critical value of theF-distribution for the desired false-rejection probability of 0.05. The coefficient of determination was greater than 0.8 for all fitted equations. All of these pointed that the obtained equations could describe the droplet size distribution correctly and predicate the size at any position in the spray sheet with precision. The fitted function research involved in this paper will provide the valuable basis to study the VMD distribution of overlapped spray sheet for boom sprayer; the study will improve the uniformity of deposition rate and biological efficacy. Meanwhile, the fine droplet zone in the spray sheet is the target of drift control. Therefore, the VMD distribution is also conducive to the development of novel anti-drift sprayer to reduce the risk of pesticide.