Spray Distribution Uniformity Research Articles

摆式主被动悬架喷雾机喷杆稳定性试验研究

When a sprayer is operating in the field, the uneven ground excitation causes the spray boom to move irregularly, significantly affecting the spray distribution uniformity and reducing the effectiveness of pesticide application. Installing a suspension between the vehicle and the boom is a crucial method to improve the boom stability. In this paper, experimental research on the stability of a boom with an active and passive pendulum suspension was carried out. The results of the transient response test of the passive suspension demonstrate that an increase in the suspension rotation damping coefficient reduces the overshoot of the system but slows down the response speed. Conversely, an increase in the suspension rotation stiffness coefficient speeds up the response speed. The results of the dynamic response test of the active suspension indicate that a smaller adjustment threshold of the control system for the boom inclination angle results in higher control accuracy. However, when the threshold is less than 1cm, the boom becomes challenging to balance. The results of the combination experiments based on the response surface method reveal that the rotation stiffness coefficient, rotation damping coefficient, unit forward speed, and their interactions significantly impact the adjustment time of the boom and the variation coefficient of the boom inclination angle. Through contribution rate analysis, the influence order of each factor on the adjustment time and variation coefficient was obtained. Additionally, the analysis of variance results show that the established regression model fits the actual situation well, and has reference significance for the design and application of the suspension.

Evaluation of droplet deposition and efficiency of 28-homobrassinolide sprayed with unmanned aerial spraying system and electric air-pressure knapsack sprayer over wheat field

Brassinolides are plant-specific Polyhydroxylated steroid hormones that play a vital role in plant growth regulation and actively participate in inducing various stress tolerance. Our objective was to investigate the influence of 28-Homobrassinolide (HBR) dosages and compare the droplet deposition of unmanned aerial spraying system (UASS) with electric air-pressure knapsack (EAP) sprayer over the wheat field. Three HBR dosages (19, 24, 30 mg a. i. ha−1) with spray volume (SV) of 15, 30 L ha−1 were applied by UASS, and HBR dosage of 24 mg a. i. ha−1 with a spray volume of 450 L ha−1 was applied by EAP. The droplet deposition of UASS 15 L ha−1 was 15.51 %, 33.57 % higher than UASS 30 L ha−1 and EAP. While spray distribution uniformity in both UASS spray volumes was less than EAP. HBR (24, 30 a. i. mg ha−1) significantly increased the photosynthetic traits, which led to a hastened grain filling rate and increased biomass of reproductive plant organs, yield, and yield components. HBR dosage of 24 mg a. i. ha−1 with a spray volume of 15 L ha−1 significantly increased grain yield by 17.94 %, 16.31 % than CK and 12.13 %, 15.31 % than EAP in two years, respectively. It is concluded that the application of HBR 24 ∼ 30 mg a. i. ha−1 with UASS 15 L ha−1 at the wheat anthesis stage could be an effective approach to improve the wheat yield.

Analysis of Spray Uniformity of Sprayers Based on Deep Belief Network

Improving spray quality has a important practical significance for controlling the drift of harmful substances, increasing the effective utilization rate of pesticides and reducing environmental pollution. The influence of factors on spray quality is analyzed, and the nozzle wear is regarded as one of the influencing factors for the first time in this paper. It also constructs the relationship between spray distribution uniformity and influencing factors Model by proposes a soft measurement method based on deep belief network. Besides, when the distribution coefficient of variation and another influencing factors is given, the pressure value corresponding to them can get by neural network inverse modeling method, And the pressure can be used as the controlled variable in the spraying process. Compared to BP, the DBN model has stronger nonlinear mapping capabilities, higher prediction accuracy, and high practical value.

Performance of new flat fan nozzle design in spray deposition, penetration and control of soybean rust

Fungicide application technology to control soybean rust (SBR) is lacking and requires optimization to improve spray coverage in the lower part of the crop canopy as well as the spray distribution uniformity. The goal of this study was to evaluate the effects of flat fan nozzles with different angles and spray volumes on the optimization of fungicide application in soybean, as well as on SBR and its effect on crop yield. For this purpose, a 2-year (2016–2018) field experiment was conducted in Botucatu, SP, Brazil. Three spray nozzles were evaluated: flat fan, double flat fan and angled flat fan, with two spray volumes. A quantitative analysis of the spray deposition was conducted, assessing the spray deposits on the lower and upper part of the plants with Brilliant Blue tracer. Furthermore, SBR severity was evaluated based on the number of pustules cm−2 and on the AUDPC, as well as the establishment of treatment control efficacy and its effect on soybean yield. Irrespective of the spray nozzles and volumes, the penetration of the droplets into the crop canopy was impaired at the reproductive stage, with less deposition in the lower part of the plant, although the larger spray volume provided greater spray deposition. All the treatments promoted effective control of the disease, with no changes in efficacy due to a larger spray volume or angled nozzles. The correct spray volume, especially with respect to the different growth stages, greatly influences spray deposition and penetration.

Development of liquid urea ammonium nitrate fertilizer foliar application system for enhanced nutrient use efficiency

A tricycle type manually operated foliar applicator was developed with ground clearance of 74.15 cm that can be operated on standing wheat crop having row spacing of 20-22 cm. The physical properties of urea ammonium nitrate (UAN) with 3% N were found nearly equal to water with respect to dynamic viscosity, surface tension and specific gravity of UAN. Based on pressure, discharges requirement and corrosiveness of UAN, reciprocating typePVC pump (2 no.) with capacity of 4.53 l/min each was selected for the sprayer. Three type of nozzles, i.e. flat fan, stream jet SJ7 and stream jet SJ3 were evaluated in terms of discharge, spray pattern and spray angle at different heights and pressures. Spray pattern and uniformity of spray distribution of nozzles (flat fan, stream jet SJ3 and SJ7) were determined on patternator test rig. Flat fan nozzles showed most uniform pattern at 2 kg/cm2 pressure and 500 mm nozzle height, whereas streamjet SJ7 showed maximum uniformity at 1.6 kg/cm2 and 600 mm height. Streamjet SJ3 nozzles were found suitable for low boom height and directed application of fertilizer. Variation in discharge of nozzles among the boom was observed less than 10% while operated in field. Field capacity of the developed foliar applicator was found 0.3 ha/h. Operating pressure of 1.5 kg/cm2 was found ergonomically suitable with an average heart rate and energy expenditure of 119 beats/min and 26.7 kJ/min, respectively for operating the prototype. The break-even point (BEP) and payback period (PBP) of developed foliar applicator were estimated as 113.43 h/year and 4 years at the operational cost of Rupees 94.68/ha.

Vibration suppression of sprayer boom structure using active torque control and iterative learning. Part II: Experimental implementation

The most common technique of protecting crops from diseases is by applying a chemical process whereby a mixture of chemicals and water are sprayed onto the crops via a sprayer. Nowadays, modern sprayers are generally implemented to suspension systems for reducing the unwanted vibration of the spray boom structure to improve the uniformity of spray distribution in the agricultural field environment. This paper serves to present a new alternative to address and resolve the vibration control problem of the moving sprayer structures. The application of an active torque control (ATC) method to cancel the undesired vibration of the sprayer boom is thus proposed. As a continuation from Part I that deals with the modeling and simulation aspect, Part II explains the practical facet of the study through the implementation of ATC and iterative learning (ATCAIL) control scheme to an experimental spray boom structure as a basis to validate the effectiveness and robustness of the scheme as simulated and described at length in Part I. A sprayer boom suspension system test rig was specifically designed and developed to verify this control scheme that was principally chosen due to its ease of implementation through the exploitation of simple proportional–integral–derivative (PID), ATC and iterative learning algorithms. The system performance was evaluated and compared to the PID and ATC–PID control schemes for benchmarking. The results demonstrate the capability of the practical ATCAIL scheme to improve the vibration suppression in both time and frequency domains, thereafter guaranteeing a more uniform spray distribution of chemicals on a bumpy terrain. The experimental outcomes are in good agreements with the simulation counterpart.

Effects of Operating Parameters for Dynamic PWM Variable Spray System on Spray Distribution Uniformity

Abstract: A dynamic PWM (Pulse Width Modulation) variable spray experiment platform was built up to study the spray distribution characteristics of PWM spray progress. The homogeneity of single nozzle dynamic spraying was evaluated based on this platform under different experiment condition. Carmine solution concentration-absorbance technology was adopted to get the CV (Coefficient of Variation) value of percent area spray coverage. RSM (Response Surface Methodology) with three variables including frequency, duty cycle of PWM control signal and forward velocity of spray was employed to study the effects of these three factors on dynamic spray distribution uniformity. Compared with previous common study of static spraying, the research on this paper can evaluate the actual spray distribution uniformity of dynamic spraying more accurately. Moreover, the platform and the research method can provide references for the settings of PWM variable-rate spray operation parameters in practical plant protection work.

Spraying systems and traveling speed in the deposit and spectrum of droplets in cotton plant

ABSTRACT Tractor traveling speed can influence the quality of spraying depending on the application technology used. This study aimed to evaluate the droplet spectrum, the deposition and uniformity of spray distribution with different spraying systems and traveling speeds of a self-propelled sprayer in two phenological stages of the cotton plant (B9 and F13). The experimental design was randomized blocks and treatments were three spraying techniques: common flat spray tips; tilted flat jet with air induction, at 120 L ha-1; and rotary atomizer disk, 20 L ha-1, combined with four traveling speeds: 12, 15, 18 and 25 km h-1, with four replications. Spraying deposition was evaluated for both leaf surfaces from the cotton plant apex and base (stage B9) and middle part of the plant (stage F13) with a cupric marker. A laser particle analyzer also assessed the droplet spectrum. The centrifugal power spray system produces more homogeneous droplet spectrum and increased penetration of droplets into the canopy in both phenological stages. Variation on the operating conditions necessary for increased traveling speed negatively influences the pattern of spraying deposits.

Evaluating droplet distribution of spray-nozzles for dust reduction in livestock buildings using machine vision

Previous studies have demonstrated the negative effects of sub-optimal air quality on profitability, production efficiency, environmental sustainability and animal welfare. Experiments were conducted to assess potential environmental improvement techniques such as installing oil-spraying systems in piggery buildings. The developed spray system worked very well and it was easy to assemble and operate. However, before selecting the most suitable spray heads, their capacity to uniformly distribute the oily mixture and the area covered by the spray heads had to be assessed. Machine vision techniques were used to evaluate the ability of different spray heads to evenly distribute the oil/water mixture. The results indicated that the best coverage was achieved by spray head No.4 and spray head No.1 which covered 79% and 67% of the target area, respectively. Spray distribution uniformity (variance) value was the lowest for spray head No.4 (0.015). Spray head No.3 had the highest variance value (0.064). As the lowest variance means higher uniformity, nozzle No.4 was identified as the most suitable spray head for dust reduction in livestock buildings. Keywords: spray head, livestock buildings, dust reduction, machine vision, spray distribution uniformity, animal welfare DOI: 10.3965/j.ijabe.20150805.1178 Citation: Mehdizadeh S A, Banhazi T M. Evaluating droplet distribution of spray-nozzles for dust reduction in livestock buildings using machine vision. Int J Agric & Biol Eng, 2015; 8(5): 58－64.

Experimental Study on Spray Uniformity of Spraying Machinery

Spray distribution uniformity is a very important performance of nozzle. This paper analyses the spray uniformity of the spraying machinery as well as the influence factors. Spray distribution coefficient of variation of nozzles varies with the different spray pressure, spray pressure and spacing. The nozzles of lechler ST made in German were tested to present the optimum spray height with different spray pressure and spray spacing through analyzing the trend of coefficient of variation varying with the different spray pressure, spray height and spray spacing. By the test, the greatest impact on spray uniformity is the pressure of the spray bar, followed by the height and the spacing of the spray bar. By analysis of the spray distribution coefficient of variation, we find the optimum combination of the spray pressure, spray height and spray spacing.

Spray distribution uniformity of different types of nozzles and its spray deposition in potato plant

Spray distribution uniformity on sampling posts and spray deposition in potato plants were investigated with six different types of spray nozzles (standard flat fan, hollow cone, air induction and twin jet hydraulic nozzles, spinning disc nozzle and air assisted rotary atomizer). Spray pressures were 4 bar for the hydraulic nozzles and 1.5 bar for the spinning disc nozzle and air assisted rotary atomizer. All trials were conducted at 6.0 km h-1 travel speed. For the spray distribution uniformity, three different sampling materials (petri dish, water sensitive paper and aluminum strip) on the sampling posts were used. Spray mixture containing water and brilliant blue was used as spray liquid. The concentration of spray samples were corrected with the calibration of the degradation of the dye exposed to direct sunlight and in a dark ambience. The air induction and twin jet nozzles had the lowest means in coefficient of variation (CV%) at all sampling materials. The highest deposit at the middle of the plants was provided with the air induction and twin jet nozzles. The hollow cone nozzle had the lowest mean in deposition at the bottom of the plants. The amount of dye with the air assisted rotary atomizer transferring the top, middle and bottom of the plants respectively, 35.2, 38.9 and 37.2% was found to be deposited on the underside of the leaves. Key words: Hydraulic nozzle, spinning disc nozzle, rotary atomizer, spray deposition, spray uniformity, potato, pesticide application.

Distribuição volumétrica de pontas de pulverização Turbo Teejet 11002 em diferentes condições operacionais

Este trabalho teve como objetivo determinar a uniformidade de distribuição para a ponta de pulverização TT 11002 em função de espaçamento entre bicos, altura de barra e pressão de trabalho, bem como avaliar a possibilidade de redução do volume de calda por meio da alteração do espaçamento entre bicos. Foram avaliados os perfis de distribuição de pontas TT 11002, para as alturas de 30, 40 e 50 cm, nas pressões de 100, 200, 300 e 400 kPa. A determinação foi realizada em mesa de teste para pontas de pulverização hidráulica, composta por canaletas em "V", espaçadas de 5 cm. Foram utilizadas, para cada configuração, 10 unidades de pontas TT 11002, instaladas isoladamente no centro da mesa. Em seguida, procedeu-se à coleta e à medição do volume pulverizado por 60 segundos e determinou-se o perfil de distribuição. A partir do perfil de distribuição em cada uma das configurações estudadas, simulou-se, utilizando programa computacional, a deposição ao longo da barra de pulverização para bicos espaçados de 40, 50, 80, 100, 120 e 150 cm. A uniformidade de distribuição foi avaliada pelo coeficiente de variação (CV), em uma barra de 12 metros de largura, onde foram utilizados os dados dos seis metros centrais. A ponta de pulverização TT 11002 apresentou boa uniformidade de distribuição (CV inferior a 7%), na pressão de 100 kPa, para bicos espaçados até 50 cm e nas alturas de barra de 40 e 50 cm. Nas pressões acima de 200 kPa, boa uniformidade de distribuição foi verificada para espaçamentos de até 50, 100 e 120 cm, para as alturas de barra de 30, 40 e 50 cm, respectivamente. A ponta TT 11002 possibilita redução de volume de calda com o aumento do espaçamento entre bicos, mantendo boa uniformidade de distribuição com maior capacidade operacional do equipamento de aplicação.

Perfis de distribuição volumétrica de pontas XR 11003 e TXVK-4 em diferentes condições de pulverização

Com o objetivo de avaliar a uniformidade da distribuição volumétrica e o efeito da angulação dos bicos na barra em pulverizações, foi conduzido experimento em laboratório, com dez unidades de cada uma das pontas de jato plano XR 11003 e de jato cônico vazio TXVK-4, fabricadas pela Spraying Systems Co. As pontas XR 11003 foram avaliadas, isoladamente, em mesa de prova para bicos construída conforme a Norma ISO 5682-1:1996, a 0,30; 0,40 e 0,50 m de altura, submetidas à pressão de 200 e 300 kPa e posicionadas com ângulos de 30º e 45º no sentido horário e anti-horário e na vertical; as pontas TXVK-4 foram avaliadas nas mesmas alturas, porém a 300 e 400 kPa, e somente na vertical. A distribuição média do volume coletado em cada configuração, das dez unidades de cada ponta, foi inserida num programa computacional, desenvolvido para o estudo, que permitiu a simulação do padrão de deposição de uma barra pulverizadora, com 24 bicos, com sobreposições variáveis, obtendo-se, ao final, o coeficiente de variação da sobreposição, o desvio- padrão e a média do volume aplicado. Os resultados sugerem a necessidade de ajustes no espaçamento entre bicos para a obtenção de melhor uniformidade na distribuição, principalmente quando se utiliza ângulo na barra; há menor influência da variação da altura da barra sobre a uniformidade da distribuição quando o espaçamento entre bicos é reduzido.

The Effects of Vertical Sprayer Boom Movements on the Uniformity of Spray Distribution

Vertical sprayer boom movements are studied with experimental modal analysis. A distinction is made between rigid-body motions and flexible deformations of the sprayer boom. Pure vertical and rolling rigid-body motions of the boom are mainly caused by unwanted tractor movements which are caused primarily by soil undulations and tyre characteristics. Flexible boom vibrations are induced by vertical and rolling angular accelerations of the tractor body.The influence of the driving speed and tyre pressure is investigated on the distinct boom motions and the effect of speed seems to dominate. Increase of driving speed (4–12 km/h) results in a rise of the pure vertical translations (130%), the rolling motions (×10) and the vertical flexible deformations (×4). A change of tyre pressure from 60 to 180 kPa leads to fall of the pure vertical translations (−20%), while the rolling and vertical flexible deformations go up by 2%. These phenomena are due to frequency shifts and larger force intensities in the frequency band between 0·5 and 3·5 Hz.The spray deposit distribution is calculated and, from the simulated spray patterns, the effect of the boom motions on uniformity of the spray pattern is examined. Simulation outcomes reveal a minor effect of the vertical translations, while rolling of the boom and vertical flexible deformations have larger influences, especially at the extremities of the boom owing to their larger amplitudes. Maximum deposits reach 760% and minimum 0% in the case of the largest sprayer boom motions. From these calculated spray patterns, an optimal range of use is determined for the tested sprayer: a spraying height of 0·5 m or more in combination with a fixed nozzle spacing of 0·5 m, a limited tractor speed and low tyre pressure leads to a good spray distribution (correct overlap) with the flat fan nozzle with top angle of 110°.

Experimental Analysis of Spray Distribution Pattern Uniformity for Agricultural Nozzles

Effects of operating pressure and nozzle height on uniformity of spray distribution pattern were investigated through laboratory experiments using five types of Teejet 11004 nozzles operated over three different heights and three different pressures. Effects of nozzle-tip materials on the uniformity was also observed. Degree of nonuniformity (DNU), which was defined using a spectral analysis, was used as the indicator of the distribution uniformity. A laboratory set-up, including a simulated boom-sprayer system, a test-condition monitoring system, and a spray-deposition measuring system, was developed. The spray-deposition measuring system used string collectors and a fluorometer to collect spray deposition data. Statistical analysis of the test data showed that nozzle height had a strong effect on spray distribution uniformity, but spray pressure had no significant effect on the uniformity. The experimental data also suggested that nozzles with nonmetal tips may provide a lower DNU than nozzles with metal tips.

An improvement of the distribution of spray from a swirl atomizer.

A spray spurted from a swirl atomizer takes the form of a hollow cone, with the dispersed spray becoming sparse in the vicinity of the center axis. In order to improve the performance, a reformed atomizer which has an orifice at the center of the swirl element was prepared for trial. The spray performance, especially the influence of the center jet issuing into the cavity formed in the vortex chamber, was investigated. As a result of the study, it was recognized that the atomizer offers a remarkable improvement of the atomizing characteristics, such as the uniformity of spray distribution and droplet size.

Factors determining the design of tractor-mounted sprayer booms—sprayer nozzle characteristics

The motion of a spray boom is a major source of variation in the distribution pattern of a sprayer. The motion is evaluated in terms of the vertical motion of the boom relative to the ground and the horizontal motion of the boom relative to the tractor. The possible effect of these movements on the uniformity of spray distribution is predicted as part of an overall strategy to improve the design of sprayer booms.

DROPLET SIZE SPECTRA, DRIFT POTENTIAL, AND GROUND DEPOSITION PATTERN OF HERBICIDE SPRAYS

Droplet size spectra and quantity of spray drift were studied for two types of flat-fan nozzles. The large orifice flat-fan nozzles operated at reduced pressure produced less drift potential; however, the spectrum of droplets was coarse. The properties of the whirl jet cone nozzles suggest that these would also produce less drift-prone material. The spray fraction likely to drift was calculated to be approximately 3–8% of the total volume of spray with the flat-fan nozzles. This was confirmed in field experiments using labelled herbicides and a liquid scintillation counting technique. A realistic pattern of the distribution of ground deposition density over a swath (obtained by field experiments), and a factor of three in density fluctuation suggest that the generally accepted concept of uniformity of spray distribution in experimental plots should be modified. Recommendations of spray drift control technique were proposed regarding the hydraulic pressure, nozzle height and orientation, travelling speed/pressure, and the size of orifice.

Spray distribution by hydraulic low-pressure fan spray nozzles fitted with a pellet

An improvement in distribution was obtained by a pellet of 3·7 mm dia inserted inside a fan spray nozzle. Experiments were carried out with individual, low pressure nozzles of 73° spray angle and three sizes, using water as spray liquid. The uniformity of spray distribution was estimated by the coefficient of variation. The difference in distribution with the pellet could be observed by the shape of the liquid sheet of the spray fan. The main characteristics of the nozzles remained about constant. A considerable change in number and size of droplets was obtained by use of the pellet.