Hollow Cone Spray Nozzle Research Articles

Deposition of spray droplets by four spray nozzles and two working pressures

The deposition of spray droplets on the target can be influenced by the type spray nozzle used, as well as the employed working pressure. Thus, with the commercial availability of new spray nozzles, performance studies with the new models become necessary. This study was carried out to evaluate ground deposition of spray droplets by four models of spray nozzles, at two working pressures. The experiment was conducted in Dourados/MS, in September 2020, with strip design and 4x2 factorial scheme, with five repetitions. Four spray nozzles were used (single flat fan, ST-IA 02 model; angle flat fan MUG 02; hollow cone MGA 02; and double flat fan ST-IA/D 02), working at 30 and 50 psi pressures. The distance between each nozzle was 50 cm, 60 cm above the ground. Water-sensitive paper was used and, immediately after application, the paper was scanned using the DropScan® tool. Subsequently, the number of droplets, coverage, amplitude, dispersion, Volume Median Diameter (VMD), Number Median Diameter (NMD), DV09, and DV01 were evaluated. The hollow cone spray nozzle provided a higher number of droplets and greater coverage compared to the other nozzles for the studied weather conditions.

Using Inpyrfluxam to Control Peanut (Arachis hypogaea L.) Foliar and Soil-Borne Diseases

Aims: To determine peanut disease control and yield response to inpyrfluxam applied at various timings during the growing season.
 Study Design: Randomized complete block design with 4 reps.
 Place and Duration of Study: Field studies were conducted from 2016 through 2020 in the south Texas peanut growing region near Yoakum (29.276o N, 97.123o W).
 Methodology: Fungicides were applied with a CO2-propellant sprayer. The spray boom was equipped with three D2-23 hollow-cone spray nozzles per row with the middle nozzle centered over each plant in the row and another nozzle located as such to spray on each side of the plant to provide thorough coverage with a spray volume was 187 L ha-1. Some studies included a non-treated control while other studies included chlorothalonil only at 1.26 kg ha-1 as the comparison treatment. Each plot consisted of four rows spaced 97 cm apart and 7.9 m long.
 Results: Inpyrfluxam applied twice in a 4 to 5 fungicide spray program in combination with chlorothalonil provided early leaf spot control as good as or better than the standards of chlorothalonil plus either azoxystrobin alone or azoxystrobin plus benzovindiflupyr applied 2 times. Control of Rhizoctonia pod rot, caused by Rhizoctonia solani Kuhn, with inpyrfluxam at 0.04, 0.05. 0.075, or 0.1 kg ai ha-1 applied 2 times during the growing season was comparable to two applications of azoxystrobin at 0.22 kg ai ha-1. Control of southern blight, caused by Sclerotium rolfsii Sacc., with one to two applications of inpyrfluxam at 0.05 to 0.1 kg ha-1 was comparable to azoxystrobin plus benzovindiflupyr. Peanut yield response was influenced by the level of soilborne and foliar disease control exhibited with each fungicide program, as those programs which provided the best control also produced the highest yield.
 Conclusion: These studies show the ability of inpyrfluxam to provide control of multiple diseases found in southwest peanut production.

Use of different spray volumes and hydraulic nozzles in air-assisted electrostatic insecticide application technologies to control coffee berry borer (Hypothenemus hampei) populations

Chemical control is essential for efficient pest management in coffee crops. Application technologies should safely deliver insecticides to the target whilst protecting the environment, insecticide applicators, and consumers. To achieve these goals, application volumes, hydraulic nozzles, and application techniques should be evaluated. This study assessed the biological efficiency of different spray volumes and spray nozzles used to apply insecticides to control coffee berry borer (Hypothenemus hampei) populations. We applied insecticides using a hydropneumatic sprayer with and without an electrostatic spraying system. The experiment followed a randomized block factorial design (2 × 2 + 1) and included two types of spray nozzles [a hollow cone spray nozzle (JA1) and a hollow cone spray nozzle with air induction (TVI)], two spray volumes (200 and 400 L ha-1), one additional treatment (SPE2 nozzle with a 200 system 200 L ha-1), and six replicates. We assessed the control efficiency of the different application methods by evaluating the percentage of fruits damaged 20 and 40 days after the date of application. The spray volume did not affect the biological efficiency of pest control, and the lower spray volume (200 L ha-1) was effective in the control of coffee berry borers. Application of insecticides using coarse droplets was more efficient than the application using very fine and fine droplets. The TVI hydraulic spray nozzle effectively controlled coffee berry borers at 200 and 400 L ha-1. The electrostatic application system performed similarly to the conventional system in terms of the control of the coffee berry borers, and was less efficient than the conventional system under some operational conditions.

Effectiveness of coffee leaf miner control associated with spray deposition in coffee leaves

ABSTRACT Coffee production faces challenges due to the susceptibility of the crop to insects. Owing to the coffee leaf miner Leucoptera coffeella, which is one of the main insect pests, the technology for the application of phytosanitary measures becomes the main challenge for coffee growers. This study aimed to evaluate the effectiveness of coffee leaf miner control using different methods of application. The study was conducted in an experimental site in the municipality of Monte Carmelo - Minas Gerais. Spray depositions in different positions of the plant canopy and the effective control of coffee leaf miner were evaluated using the following application treatments: a hydropneumatic sprayer with varying spray volumes (200 and 400 L ha-1), two hollow-cone spray nozzles with the presence and absence of agricultural adjuvant, and electrostatic application using a spray volume of 200 L ha-1 with and without spray adjuvant. The addition of an adjuvant to the spray did not influence coffee leaf miner control; in contrast, a spray volume of 200 L ha-1 combined with the application of coarse droplets was efficient in the management of insect pest. The reduction in the rate of the application using coarse droplets increased the operational capacity and reduced spray drift potential.

Caracterização da pulverização de fungicida na cultura do trigo com pontas hidráulicas e atomizadores rotativos de discos

O objetivo deste trabalho foi avaliar as características de pulverização de pontas hidráulicas e atomizadores rotativos de discos, utilizando diferentes volumes de calda, na cultura do trigo, bem como seus rendimentos operacionais. Foram realizados dois experimentos, nas safras agrícolas de 2009 e 2010. No primeiro ano, utilizou-se da cultivar Fundacep 30, e no segundo das cultivares Pampeano e Nova Era. As pontas testadas foram do tipo leque e cone vazio, ambas com volume de calda de 120 L ha-1, e atomizadores rotativos de discos utilizando baixo volume oleoso (BVO®), com volumes de calda de 24 e 34 L ha-1. Os parâmetros avaliados foram densidade de gotas (DG) e diâmetro mediano volumétrico (DMV) nos terços superior, médio e inferior, através da análise de cartões hidrossensíveis. Também foi calculada a capacidade operacional para os tratamentos. Os resultados mostraram que os atomizadores rotativos de disco com 24 L ha-1 apresentaram a maior DG no terço superior; entretanto, não houve diferença entre os tratamentos para os demais terços avaliados. Atomizadores rotativos de disco apresentaram gotas de menor DMV em comparação com as pontas hidráulicas, sendo que estas apresentaram grande heterogeneidade de gotas. A maior capacidade de campo operacional foi obtida com uso de atomizadores rotativos de disco, devido ao menor volume de calda utilizado por este equipamento.

Visual Study of Hollow Cone Water Spray Jet Breakup Process at Elevated Temperatures and Pressures

The liquid jet breakup is a ubiquitous phenomenon in nature and a classic problem in hydrodynamics. The understanding of the jet breakup mechanism of hot liquids is still a challenge for researchers. The objective of this work was to understand and control the hot water spray jet breakup mechanism at moderate pumping pressures and elevated temperature. For this purpose, the visual and comparative studies were conducted on hollow cone water spray patterns generated by three hollow cone spray nozzles which were installed in an in-house built intermittently forced liquid spraying system. Using a high speed camera, the jet breakup dynamics were visualized as a function of system input parameters. The analysis of the grabbed images confirmed the strong influence of these processing parameters on spray characteristics. It was also predicted that heated liquids generate the dispersed spray patterns and the induction of thermal energy into the system enhances the jet disintegration ability. The spray cone width and angle were not varied significantly whereas the Weber and Reynolds numbers along with other spray parameters showed an appreciable response to the load pressure and water heating temperature at early stages of water injection.

Tamanho de gotas de pontas de pulverização em diferentes condições operacionais por meio da técnica de difração do raio laser

O presente trabalho objetivou avaliar o espectro de gotas de pontas de pulverização hidráulicas, submetidas a diferentes pressões e composições de calda, por meio de um analisador de partículas a laser. Em delineamento inteiramente casualizado, avaliaram-se duas pontas de jato plano duplo com indução de ar (AD-IA/D 11002 e AD-IA/D 11004) e duas pontas de jato cônico vazio (MAG - 2 e MAG - 4), em esquema fatorial 3 x 2: três pressões de pulverização (207, 276 e 345 kPa para as pontas de jato plano duplo e 414; 483 e 552 kPa para as pontas de jato cônico); e duas composições de calda (água e água mais o adjuvante fosfatidilcoline + ácido propiônico). A adição do adjuvante reduziu o diâmetro da mediana volumétrica das gotas pulverizadas pelas pontas AD-IA/D 11002 e 11004; porém, teve efeito inverso com a ponta MAG - 4 e não o alterou com a ponta MAG - 2. Em condições climáticas adversas, não se recomenda o uso de pontas de jato cônico vazio, mesmo com a adição do adjuvante testado, em virtude do alto risco potencial de deriva.

Numerical modeling of an evaporative spray in a riser

A numerical model is developed for modeling the evaporative spray in a hot gas–solid flow. Phenomenological sub-models for the interaction between the cold evaporative spray droplets and hot particles, including momentum exchange, heat and mass transfer, are proposed based on previous experimental and numerical studies in the literature. Simulation of an evaporative water spray through a hollow cone spray nozzle in a riser operated at an elevated temperature is conducted. Comparison with available experimental measurements in terms of the spray expansion and spray width is performed, and reasonable agreement is obtained. The effect of various parameters introduced into the model is investigated in parametric studies, and appropriate values for those parameters are suggested. In addition, influences of various operating conditions including droplet size, bed temperature, and spray angle are evaluated.

Efeito de pontas de pulverização no controle químico da ferrugem da soja

O controle químico eficiente da ferrugem asiática da soja depende da correta seleção da ponta de pulverização. Este trabalho teve o objetivo de avaliar o efeito da utilização de diferentes pontas de pulverização na aplicação de fungicida para o controle da ferrugem da soja. O ensaio foi conduzido no delineamento em blocos ao acaso, com quatro repetições, em esquema fatorial (4 x 2) + 1: quatro tipos de ponta de pulverização (jato plano defletor duplo, jato plano duplo com pré-orifício e jato cônico vazio com e sem indução de ar), dois volumes de aplicação (150 e 200 L ha-1) e um tratamento adicional que não recebeu fungicida. Realizou-se a semeadura direta da cultivar de soja M-SOY 8008 (ciclo precoce), avaliando-se, após a aplicação do fungicida tebuconazole, a deposição de calda no dossel da cultura, a severidade da ferrugem, o grau de desfolha e a produtividade. Concluiu-se que não houve influência dos tipos de pontas de pulverização e dos volumes de calda no controle da ferrugem. Na parte inferior do dossel, a cobertura proporcionada com a utilização das quatro pontas foi inferior a 7% da área, sendo, portanto, necessário buscar estratégias que incrementem essa deposição. O fungicida reduziu a severidade da ferrugem da soja, o que refletiu na produtividade, que foi, em média, 157% superior à obtida na testemunha.

The atomization of viscoelastic fluids in flat-fan and hollow-cone spray nozzles

This article reports experimental observations of the flow kinematics and stability of thin fluid sheets produced by a series of commercially available flat-fan and hollow-cone spray nozzles for a series of viscoelastic wormlike micelle solutions. As the flow rate through the nozzle is increased, the sheets of viscoelastic fluid grow larger and eventually becoming unstable and atomizing into drops. For the sheets of water produced by the flat-fan nozzles, the fluid rims of the sheets were found to destabilize first. The addition of viscoelasticity was found to stabilize the rim while simultaneously destabilizing the internal fluid sheet. What results is a series of novel flow structures comprised of highly interconnected filaments created by the growth of multiple internal holes that develop within the fluid sheet. Increasing viscoelasticity of the test fluid was found to stabilize the thin films produced by both the flat-fan and hollow-cone spray nozzles, thereby shifting the break-up of the sheets to larger flow rates. However, beyond the critical flow rate for sheet rupture, increases to the fluid elasticity were found to alter the dynamics of the atomization of the viscoelastic fluid sheets by increasing the number and growth rate of holes in the sheet while simultaneously reducing the initiation time for sheet rupture.

Avaliação do espectro de gotas de pontas de pulverização hidráulicas utilizando a técnica da difração do raio laser

As pontas de pulverização são os componentes mais importantes dos pulverizadores na aplicação de agrotóxicos. Dessa forma, este trabalho teve como objetivo avaliar o espectro de gotas de pontas de pulverização hidráulicas de jato plano (standard e antideriva) e de jato cônico vazio, disponíveis no mercado, submetidas a diferentes pressões da calda. Em ambiente controlado, avaliou-se o espectro de gotas, por meio de um analisador a laser de gotas em tempo real, nas pressões de 200; 300 e 400 kPa para as pontas de jato plano, e de 400; 500 e 600 kPa para as pontas de jato cônico. Os resultados permitiram concluir que: o espectro de gotas foi influenciado pela vazão nominal das pontas e pela pressão da calda; o potencial de deriva das pontas de jato plano standard e de jato cônico vazio foi alto; o uso de pontas de pulverização antideriva dotadas de pré-orifício aumentou o diâmetro das gotas, constituindo-se, portanto, em fator auxiliar para a redução da deriva nas pulverizações, e a avaliação do espectro de gotas empregando-se a técnica da difração do raio laser mostrou-se rápida e precisa.

Parametric study of no production via quantitative laser-induced fluorescence in high-pressure, swirl-stabilized spray flames

We report the influence of equivalence ratio and air preheat temperature on nitric oxide (NO) concentration in high-pressure heptane spray flames. The burner used was based on the lean direct-injection design and incorporated a pressure-atomized hollow-cone spray nozzle. Helical vanes in the air passage coupled with a divergent exit and preheated air produced a strongly swirling, clean blue flame. NO concentration profiles were measured at 4.27 atm using laser-induced fluorescence (LIF) at five axial heights above the burner. The uniformity of NO throughout the central region of the flame demonstrated the well-mixed nature of the recirculation zone. Measurements were taken at the 40 mm centerline height to determine the effects of primary equivalence ratio (φp=1.0 to 0.8) and air preheat temperature (Tair=375 K to 575 K). The results strongly suggest that NO formation occurs in near stoichiometric regions of the flame and is subsequently diluted with excess air. A residence time effect is evident and apparently scales as the mass flow rate of air relative to that for stoichiometric combustion, yielding a φP2 scaling of the NO (ppm). Moreover, moderate increases in preheat temperature produce significant increases in NO (ppm) levels, suggesting thermal NO production.

Experimental studies of spray evaporation in turbulent flow

Abstract A number of processes in the chemical industry and in combustion science involve the evaporation of atomised liquids in a turbulent environment. To allow an optimisation of such processes and to provide data for the validation of numerical calculations, the spray evaporation in a heated turbulent air stream was studied experimentally. The flow configuration was a pipe expansion with an expansion ratio of 3, where heated air entered through an annulus with the hollow cone spray nozzle being mounted in the centre. In the experiments isopropyl alcohol was used as a liquid because of its high evaporation rate. Measurements were taken for different flow conditions, such as air flow rate, air temperature, and liquid flow rate in order to provide a set of reliable data. Phase-Doppler anemometry (PDA) was applied to obtain the spatial change of the droplet size spectrum in the flow field and to measure droplet size–velocity correlations. From these local measurements profiles of droplet mean velocities, velocity fluctuations and droplet mean diameters were obtained by averaging over all droplet size classes. Moreover, recent extensions of the PDA signal processing allowed for accurate determination of the droplet mass flux, from which also the global evaporation rates could also be determined. The data for the different flow conditions also include the inlet conditions for air flow and spray (i.e., for all three velocity components), inlet temperature, and wall temperature profiles. The latter were measured using a thermocouple with a special wall sensor.

Quantitative laser-saturated fluorescence measurements of nitric oxide in a heptane-fueled lean direct-injection spray flame at varying global equivalence ratios

We report the influence of equivalence ratio on nitric oxide (NO) concentration profiles in an unconfined heptane spray flame at atmospheric pressure. The associated burner is based on the lean direct-injection design and incorporates a pressure-atomized, hollow-cone spray nozzle. Helical vanes in the air passage coupled with a divergent exit and preheated air produce a strongly swirling, clean, blue flame. NO concentration profiles are measured using laser-saturated fluorescence (LSF) at four axial heights above the burner. Because of the liquid droplet environment, an extension of LSF utilizing a Mie-scattering back-ground subtraction technique is required to make quantitative measurements of NO concentration. The NO profiles are measured in three flames with global equivalence ratios of 1.0, 0.9, and 0.8. Probe measurements of CO 2 and O 2 mole fractions are used to determine representative effective equivalence ratios, which are lower than the global equivalence ratios because of significant entrainment of ambient air Through an analysis of area-averaged NO concentrations at various axial heights, the downstream [NO] is found to be mainly redistributed as the flame spreads owing to the intense recirculation of combustion products. Moreover, comparisons of [NO] profiles as a function of equivalence ratio demonstrate that dilution air is a large influence in the reduction of NO concentration at equivalence ratios leaner than stoichiometric.

Effect of Leafspot Fungicides on Twospotted Spider Mite in Virginia Peanut, 1995

Abstract Selected fungicides were evaluated for effect on TSSM in cv. ‘NC-V 11’ Virginia-type peanut in Isle of Wight, VA. Comite 6, known to be efficacious against mites, was included for comparison. Peanuts were planted on 6 May using a 36-inch row spacing. Treatments were applied on 28 Jul and again on 11 Aug using a CO2 pressurized backpack sprayer calibrated to deliver 14.5 gpa at 50 psi through three D2-13 disc-core hollow cone spray nozzles per row, 1 over the top and 1 on each side. A RCB experimental design was used with 4 replicates; plots were 4 rows by 20 ft. Treatments were evaluated on 28, 31 Jul and on 3, 7, 11, 16 and 22 Aug by comparing the number of live mites in a 1.5 cm diam area on 2 randomly selected leaflets per plot. Mite counts were made in the field using lOx magnification lenses. Data were analyzed using ANOVA and LSD statistical procedures. Cumulative mite-days (CMD) were calculated for each treatment over the entire test period using Σ(Xi+1 - Xi)[(Yi + Yi+1)/2], where Xi and Xi+1 are adjacent sample dates and Yi and Yi+1 are corresponding points of mean mite number per leaflet.

Effect of Selected Insecticide/Acaricides on Twospotted Spider Mite in Virginia Peanut, 1995

Abstract Selected insecticide/acaricides were evaluated for efficacy against TSSM in cv. ‘NC 7’ Virginia-type peanut in Isle of Wight County, VA. Peanuts were planted on 4 May using a 36-inch row spacing. All treatments were applied on 28 Jul. The Comite + 5 d treatment was applied again on 5 Aug. Karate, at the 0.025 and 0.04 lb (AI)/acre rates, Capture C, and Danitol were applied again on 9 Aug. All were applied using a CO2 pressurized backpack sprayer calibrated to deliver 14.5 gpa at 50 psi through three D2-13 disc-core hollow cone spray nozzles per row, 1 over the top and 1 on each side. A RCB experimental design was used with 4 replicates; plots were 4 rows by 15 ft. Treatments were evaluated on 28, 31 Jul and on 3, 7, 11, 16, 22 and 29 Aug by comparing the number of live mites in a 1.5 cm diam area on 2 randomly selected leaflets per plot. Mite counts were made in the field using 10x magnification lenses. Data were analyzed using ANOVA and LSD statistical procedures. Cumulative mite-days (CMD) were calculated for each treatment over the entire test period using Σ(Xi+1 – Xi)[(Yi + Yi+1)/2], where Xi and Xi+1 are adjacent sample dates and Yi and Yi+1 are corresponding points of mean mite number per leaflet.

Selected Biological Insecticides for Corn Earworm Control in Soybean in Virginia, 1993

Abstract Efficacy of selected biological insecticides was evaluated against CEW in soybean. All treatments were applied on 12 Aug, and all treatments, except Larvin 3.2 were applied again on 17 Aug. Treatments were applied as sprays with water using a CO2 pressurized backpack sprayer calibrated to deliver 14.5 gal formulation per acre at 50 psi through three D2-13 disc-core hollow cone spray nozzles per row, 1 over the top of the row and 1 on each side. A RCBD was used with 4 replicates; plots were 4 rows × 40 ft. Treatments were evaluated 3 h before and 4, 8, 11 and 14 DAT from 12 Aug by comparing numbers of small (1st and 2nd instars), medium (3rd and 4th instars), large (5th and 6th instars) and total larvae per 3 row ft using a standard beat cloth sampling technique. Data were analyzed using ANOVA and LSD statistical procedures. A cumulative index was calculated for each treatment using ∑(Xi+1 - Xi)(Yi + Yi+1)/2], where Xi and Xi+1 are adjacent sample dates and Yi and Yi+1 are corresponding points of total larval number.

Control of Twospotted Spider Mite in Peanut, 1993

Abstract Selected pesticides were evaluated for control of TSSM in cv. ‘NC-10’ Virginia-type peanut in Suffolk, VA. Peanuts were planted using a 36-inch row spacing. Treatments were applied on 28 Jul and again on 10 Aug using a CO2-pressurized back-pack sprayer calibrated to deliver 14.5 gal formulation per acre at 50 psi through three D2-13 disc-core hollow cone spray nozzles per row, 1 over the top and 1 on each side. A RCBD was used with 4 replicates; plots were 4 rows × 20 ft. Treatments were evaluated on 28, 30 Jul and on 3, 5, 10, 13, 20, and 29 Aug by comparing the number of live mites in a 1.5 cm diam area on 4 randomly-selected leaflets per plot. Mite counts were made in the field using 10X magnification lenses. Data were analyzed using ANOVA and LSD statistical procedures. A cumulative index (CI) was calculated for each treatment using ∑(Xi+1 - Xi)[(Yi + Yi+1)/2], where Xi, and Xi+1, are adjacent sample dates and Yi and Yi+1, are corresponding points of total mite number.

Selected Insecticides for Corn Earworm Control in Soybean in Virginia, 1993

Abstract Efficacy of selected insecticides, with and without adjuvants, was evaluated against CEW in soybean. Hutcheson soybean was planted in 36-inch rows on 29 Jun. Treatments were applied on 18 Aug with water using a CO2-pressurized backpack sprayer calibrated to deliver 14.5 gal formulation per acre at 50 psi through three D2-13 disccore hollow cone spray nozzles per row, 1 over the top of the row and 1 on each side. A RCBD was used with 4 replicates; plots were 4 rows × 40 ft. Treatments were evaluated 3 h before and 1, 5, 8 and 12 DAT by comparing numbers of small (1st and 2nd instars), medium (3rd and 4th instars), large (5th and 6th instars) and total larvae per 3 row ft using a standard beat cloth sampling technique. Yield was determined by combining the center 2 rows of each plot (80 row ft) using a Hege small-plot combine. Data wore analyzed using ANOVA and LSD statistical procedures. A cumulative index (CI) was calculated for each treatment using ∑(Xi+1 - Xi)(Yi + Yi+1)/2], where Xi, and Xi+1, are adjacent sample dates and Yi and Yi+1 are corresponding points of total larval number.

Selected Insecticide Evaluations for Control of Fall Armyworm in Peanut, 1992:

Abstract Selected insecticides were evaluated against FAW in Virginia-type peanut in Greensville County, VA. Peanuts were planted 15 May using a 36-inch row spacing. Test treatments were applied on 24 Aug using a CO2 pressurized backpack sprayer calibrated to deliver 14.5 gal/acre at 50 psi through 3, D2-13 disc-core hollow cone spray nozzles per row, 1 over the top and 1 on each side. A RCB experimental design was used with 4 replicates; plots were 4 rows by 30 ft. Treatments were evaluated before and 1 and 4 DAT by comparing numbers of small, medium, and large-sized FAW larvae per 3 row ft, corresponding to lst-2nd, 3rd-4th, and 5th-6th instar groupings, respectively. A standard or rigid beat cloth was used in each plot to determine number of worms per 3 row ft. Data were analyzed using ANOVA and LSD procedures.