Distribuição volumétrica e espectro de gotas de pontas de pulverização de jato cônico vazio DDC2 novas e usadas

Abstract

Resumo -A aplicação eficiente de defensivos agrícolas, sem prejuízos ao meio ambiente, depende de uma série de fatores, sendo um deles a utilização de pontas de boa qualidade. Objetivou-se com este trabalho avaliar a vazão, a distribuição volumétrica e o espectro de gotas das pontas de pulverização hidráulica novas e usadas sob diferentes condições operacionais. A distribuição volumétrica foi determinada em bancada de ensaios padronizada utilizando pressões de 400, 600 e 800 kPa, altura de 0,50 m em relação à bancada e espaçamento entre pontas de 0,50 m. Em ambiente controlado, avaliou-se o espectro de gotas, por meio de um analisador a laser de gotas em tempo real, nas pressões de 400, 600 e 800 kPa. As médias das vazões proporcionadas pelas pontas em uma mesma pressão foram significativamente diferentes na pressão de 800 kPa entre pontas novas e usadas, sendo respectivamente 0,85 e 0,97 L min -1 . As pontas usadas apresentaram vazão 10% acima daquela informada pelo fabricante. O coeficiente de variação da distribuição indicou que as melhores distribuições ocorrem para pontas novas com pressão de trabalho não superior a 400 kPa. Houve diferença significativa da vazão na pressão de 800 kPa entre pontas novas e usadas, sendo respectivamente 0,85 e 0,97 L min -1 . Palavras-chave -Tecnologia de aplicação. Tamanho de gotas. Pressão de trabalho.Abstract -The efficient application of pesticides without harming the environment depends on a number of factors, one of them being the use of nozzles quality. This study aimed to evaluate the distribution profile and droplet spectra ofnew and used low drift spray nozzles under different operational conditions. The volumetric distribution was determined on a test table at 400, 600 and 800 kPa pressures, height of 0,50 m in relation to the patternator and nozzle spacing from 0,50 m. In a controlled environment, droplet spectrum, using a real time laser particle size analyzer, was measured with the operating pressure of 400, 600 and 800 kPa. Analyzing the resultsof the meanflowprovided by spray nozzles, for the same pressure, there was a significant difference inpressurebetween800 kPa new and used nozzles, respectively 0.85 and 0.97 L min -1 . The flow values found for the spray nozzles used had flow 10% above that reported by the manufacturer. The coefficient of variation of the distribution indicated that the best distributions occur with new spray nozzles for working pressure not exceeding 400 kPa. There were significant differences in the flow pressure of 800 kPa between new and used nozzles, being respectively 0.85 and 0.97 L min -1 .

Droplet Spectrum Produced in Pumpkin Cultures Submitted to Different Forms of Spraying

“…However, the formation of thick and very thick droplets is possible, resulting in increased drainage of the solution and, consequently, reduced spray efficiency (Lesnik et al, 2005). Furthermore, according to Heinkel et al (2000) and Vitória and Leite (2014), the use of air induction nozzles can provide a similar performance to that of conventional spraying (with single flat spray nozzles), as long as the spray operator receives information regarding how to initially select the nozzle and how to improve its performance.…”

“…Regarding the nozzles that operate with hydraulic pressure, the production of significantly uneven drops has been described, which hampers adequate target coverage. The development of technologies that produce more uniform drops is required in order to reduce the number of extremely small or large droplets (Vitória & Leite, 2014). The adoption of spray equipment that employs rotating atomizers as a drop-breaking system is an option.…”

Influence of working pressure and spray nozzle on the distribution of spray liquid in manual backpack sprayers

“…For the hollow cone models, values reported in the literature are even higher than those found in this research, because of the characteristics of the model and form of spray distribution and droplet formation. For CDD (ceramic diffuser disc) models, CVs were found to be more than 14% for new tips and more than 24% for used tips at a pressure of 4 bar (VITÓRIA et al, 2014). This may indicate poor quality of the material and even the need for a replacement of the tips being used.…”

“…However, they are not always used according to the best agronomic practices; there is a need for development of operational procedures, adequacy of accessories and improvement of ergonomic aspects (FREITAS, 2006;SASAKI et al, 2013;VITÓRIA et al, 2014).…”

Espectro Das Gotas Produzidas Por Pontas De Jato Plano Duplo Defasado Com Indução De Ar

“…Este comportamento corrobora com os resultados obtidos por Vitória et al (2014), que utilizaram pontas hidráulicas do tipo cone vazio. Para uma determinada ponta de pulverização hidráulica, a vazão de líquido é diretamente proporcional à raiz quadrada da pressão (TADIĆ et al, 2014…”