Spray Units Research Articles

Design and Spray Performance Evaluation of an Air–Ground Cooperation Stereoscopic Plant Protection System for Mango Orchards

With the aim of solving the problems of high labor intensity, low operational efficiency, and poor deposition distribution uniformity in the mango canopy associated with traditional plant protection devices, an air-ground co-operation stereoscopic plant protection system consisting of an orchard caterpillar mist sprayer and a six-rotor plant protection UAV was designed to jointly undertake plant protection operations in mango orchards. We tested the spraying performance of the system on mango trees, compared with the single-machine operation, the air–ground co-operation system could significantly increase the droplet coverage on the upperside of mango leaves in each part of the canopy (a 14.7% increase for the mist sprayer and 12.9% for the UAV). This increased the active component deposition distribution uniformity in the mango canopy but could not significantly improve the deposition and coverage of droplets on the underside of leaves compared with the mist sprayer and plant protection UAV. Due to the characteristics of the mango canopy such as large leaf length and thickness and complex leaf inclination distribution, this led to poor deposition distribution uniformity of the two spray units, and the overall CV was over 150%. The pesticide active ingredients were almost uniformly distributed in the vertical direction when the application ratios (ground implements/plant protection drones) were 8/2 and 7/3, offering a promising protocol for reduced pesticide application in mango orchards. This study presents promising data that support the innovative integration of drones into crop protection programs for large canopy crops (e.g., mango) and provides guidance for the ACSPPS system in reduction and precision application research.

Тритій у водних об’єктах району Южно-Української атомної електростанції

Based on the results of radioecological studies in the aquatic ecosystem of the South-Ukrainian Nuclear Power Plant region (SUNPP), the tritium content in technological reservoirs (cooling pond, biological pond of the cleaning station, splash pool) and adjacent surface and groundwater bodies were analyzed. It is shown that the average annual volumetric activity of tritium in the water of technological reservoirs of the SUNPP during 2014 - 2018 is kept at the level of 110 - 160 Bq/l, with a tendency to increase with an average annual rate of 12 - 13 Bq/l, which correlates with a decrease in the volume of blowdown water discharge from the cooling pond (about 8698 thousand m3 per yr). Higher levels of volumetric activity of tritium were registered in the water of technical wells - leakage markers in the technical system, which, moreover, are fed from the pools of cooling towers and spray units. The tritium content in the bioponds of the sewage system of the SUNPP decreased from more than 1000 Bq/l in the early 1990s to 100 - 130 Bq/l in 2017 - 2018, which led to a decrease in its level in the Trikratsky reservoir and should affect lowering its level in groundwater sources, which are located below the natural runoff. Taking into account the physicochemical properties of tritium and the conclusions of well-known scientists about the extremely rapid accumulation of tritium in the environment, the necessity of hydroecological monitoring of the tritium content in surface water bodies is substantiated, the water of which is used for irrigation of agricultural crops and which are hydrodynamically connected with the technological water bodies of the SUNPP, as well as sources of drinking water located downstream of the natural runoff from the technological reservoirs of the nuclear power plant.

Aerodynamic model of centrifugal cleaning in a once-through cyclone

This work examines aerodynamic modeling of the process of air cycloning in a direct-flow cyclone. The most important technological operation in the food industry is to achieve a high degree of dusty air purification. The practice of operating cyclones testifies to the discrepancy between the actual efficiency of the apparatus and the real capabilities of dust collecting installations. The modern development of industry is characterized by an ever-increasing intensification of various technological processes, which is accompanied by significant dust formation. The problem of collecting dust affects almost all branches of modern production. These are the production of building materials, metallurgy, woodworking, chemical and food industries. In this regard, the problem of maintaining the cleanliness of the air basin of cities arises, and increased requirements are imposed on dust-collecting equipment. Along with the requirement to ensure minimum dust emissions, dust-collecting equipment should be completely reliable for a long time of operation and not require large costs for installation and maintenance. For dust collection of dust, cyclones are now widely used, the principle of which is based on centrifugal separation of the mixture. In the food industry, the most widespread are cyclones of spray units “Niro-Atomizer”, “VRA-4”, “Nema-500”, A1-ORCH. The cyclones of the listed installations differ from each other in the number of devices installed in the dust collection system, design features and aerodynamic modes of air purification.

Design and optimization of spray unit holder and shaft assembly of a linear motor operated spray gun

In order to reduce the labor and production cost, linear motor operated automatic spray gun has been designed and developed. This spray gun consists of 2 spray units, spray unit holder and shaft assembly an air control and supply unit and a triggering unit to carry out the multiple spray operations. This study focuses on the design optimization and fabrication of the spray unit holder and shaft assembly. There are 2 links to this holder and they are 90° apart from each other. One end of the holder links are used to hold the spray units and the other ends are attached with a shaft. The shaft is kept in position in the spray gun body by the adjusting lever and can rotate 90° to either side. Due to this rotation, the position of spray units can be adjusted during the desired spray operation. Since, the highly pressurized fluid is passed through the spray unit, a high force is subjected to the end of the holder where the spray unit is held and the holder behaves like a cantilever beam. Meanwhile, the shaft is subjected to the bending moment and the torque due to the fluid pressure and the weight of the spray unit, respectively. After analyzing, dimensions and material selection have been optimized in order to fabricate the spray unit holder and shaft assembly. During the performance test, it is observed that the fabricated spray unit holder and shaft assembly can support the spray operation without any deflection and failure.

Design and optimization of the housing of spray unit of a linear motor operated spray gun

Pneumatic system is normally used to trigger the automatic spray gun for conventional spray operations. Highly skilled labors and a number of adjustable knobs are required to produce the high quality coating works using the conventional automatic spray gun which is cost intensive. Therefore, linear motor operated multiple spray operations spray gun has been developed. This spray gun consists of two spray units, an air control and supply unit and a triggering unit to carry out the multiple spray operations. This paper focuses on the design optimization and fabrication of the housing of the spray units which hold fluid nozzles, air nozzles, an assembly cap, a needle valve or a ball valve. In the air less and air assisted airless spray systems, high pressurized liquid is passed through the nozzle which is held by the housing of the spray unit. Before entering into the nozzle, the high pressurized liquid is passed through the housing. For the simplicity of the analysis, it is assumed that the housing is an open-ended pressure vessel. From the analysis, dimensions and material selection have been optimized and finally the spray units have been fabricated and tested. During the performance test it is seen that satisfactory transfer efficiency of spray operation has been achieved by using newly developed spray housing of the spray units, which proves the stability of the spray housing during high pressure operation.

Design and Optimization of the Housing of Spray Unit of a Linear Motor Operated Spray Gun

Pneumatic system is normally used to trigger the automatic spray gun for conventional spray operations. Highly skilled labors and a number of adjustable knobs are required to produce the high quality coating works using the conventional automatic spray gun which is cost intensive. Therefore, linear motor operated multiple spray operations spray gun has been developed. This spray gun consists of two spray units, an air control and supply unit and a triggering unit to carry out the multiple spray operations. This paper focuses on the design optimization and fabrication of the housing of the spray units which hold fluid nozzles, air nozzles, an assembly cap, a needle valve or a ball valve. In the air less and air assisted airless spray systems, high pressurized liquid is passed through the nozzle which is held by the housing of the spray unit. Before entering into the nozzle, the high pressurized liquid is passed through the housing. For the simplicity of the analysis, it is assumed that the housing is an open-ended pressure vessel. From the analysis, dimensions and material selection have been optimized and finally the spray units have been fabricated and tested. During the performance test it is seen that satisfactory transfer efficiency of spray operation has been achieved by using newly developed spray housing of the spray units, which proves the stability of the spray housing during high pressure operation. Keywords: Spray Gun, Spray Process, Design, Pressure Vessel, Failure Analysis, Deflection Analysis.

Spraying starch to improve strength of containerboard produced from weak recycled furnish

Producers of recycled furnish–based testliner and corrugating-medium grades often struggle to reach required strength properties compared to producers of packaging grades produced from virgin fibers. Starch can be used on a size press to compensate for the lost fiber strength, weakened from recycling. However, conventional size-press technologies have limitations when large starch pickup amounts are targeted, or when speeds are relatively high in modern packaging board machines. Spray sizing overcomes many roadblocks, and sufficient strength improvements are achieved for recycled testliner and corrugated medium. Dongil Paper Manufacturing Co. Ltd. in South Korea is a pioneer in the use of spray technology, with three spray units already in production. The spray device provides a large window for starch application and gives an exceptional transfer rate to the web. Clean operation, no wearing parts, and ease of running are other advantages when operating a starch-spray device. The theoretical provisions for effective starch transfer to the web and control of starch penetration are described in this paper. The theories are supported by pilot trial results as well as production experience. Starch application with spray is a new and innovative approach for producing packaging board grades economically from a fully recycled fiber source.

Plant Species Richness on a Transmission Right-of-Way in Southeastern Pennsylvania, U.S. Using Integrated Vegetation Management

The Green Lane Research and Demonstration Area, Montgomery County, Pennsylvania, U.S., has been studied each year since 1987, making this 21-year-old project extremely valuable as a source of information on the effects of mechanical and herbicidal maintenance on flora and fauna along an electric transmission right-of-way (ROW). In this article, our objective was to document plant species richness among treatment units and in relation to wire and border zones on the ROW. We noted the presence of plant species from late May through mid-August in 2005 and 2006 and observed 114 vascular plant species in the ten treatment units; 35 (31%) of these species were exotic. Twenty-seven (24%) species were widespread on the ROW and seven of these (26%) were exotic. The total number of species per unit ranged from 46 (40%) species in handcut units to 57 (50%) in stem–foliage spray units. Of the total number of species, 103 (90%) and 81 (71%) occurred in wire and border zones, respectively. The number of exotic species was higher in wire zones (33 [29%]) than in border zones (22 [19%]).

Development of a Trigger-On Indicator for a Weed Sensing Spray Unit

Intermittent spray systems that automatically spray only when weeds are present have been commercially available since 1992 and can significantly reduce herbicide usage by 50 to 90% as compared to broadcast applications (2). The Weedseeker (NTech Industries, Ukiah, Calif.) is one such system that utilizes optics to detect the presence of weeds. The system works by exploiting the fact that chlorophyll selectively absorbs red wavebands of light and reflects near-infrared light (1). Each sensor unit has its own built-in light source and a sensor that detects the light reflected back to the unit over a 12-inch-wide field of view. When the sensor detects an increase in the ratio of near-infrared to red light above the base threshold level, a solenoid valve is activated to spray the weed. Although the sensor unit reliably detects the presence of green plants (2), a major drawback with the current design is that it doesn't provide any feedback to the user when one of the spray units is actively spraying. This is problematic, particularly on wide-boom, multi-sensor-unit sprayers since each sensing unit is calibrated independently in the field prior to spraying from the reflectance of the ground surface beneath it whenever the calibration button is pushed. If one of the sensing units is calibrated when the sensor is over a weed, the unit will not detect weeds of similar size or smaller when spraying. Also, because the sensing unit is sensitive to background reflectance, if one of the sensors is calibrated when it is positioned over a spot of ground that is not characteristic of the rest of the field, the unit will ghost fire and spray when weeds are not present. Either scenario is undesirable, but likely to occur since recalibration is necessary several times during the day due to changes in ambient light and field conditions. To overcome this problem, a trigger-on indicating device was developed to help the operator determine that the sensor units are operating correctly. The Weedseeker unit has a small LED on the back of the unit that illuminates whenever the unit is spraying. The device developed utilizes a phototransistor to detect when the LED is illuminated and activate a super-bright LED that is visible from the tractor cab (Fig. 1). The circuit designed includes a resistor and a NPN transistor that function to prevent low levels of light from activating the super-bright LED (Fig. 2). All electronic components are encased in a waterproof BUD box and attached to a Weedseeker sensor via Velcro and zip ties (Figs. 1 and 3). An opaque, nontranslucent flexible rubber washer is used to seal the phototransistor from ambient light and dust (Fig. 1). Power is supplied by two 1.5-V, AA batteries. Fig. 1. Trigger-on indicator assembly for Weedseeker sensor unit.

Plant Species Richness On An Electric Transmission Right-Of-Way Using Integrated Vegetation Management

The State Game Lands (SGL) 33 Research and Demonstration Area, Centre County, Pennsylvania, U.S., has been studied each year since 1953, making this 52-year old project extremely valuable as a source of information on the effects of mechanical and herbicidal maintenance on flora and fauna along an electric transmission right-of-way (ROW). A desired objective of integrated vegetation management on the SGL 33 Research and Demonstration Area is to create a diversity of plant species. In this paper, our objective was to document plant species richness among treatment units and in relation to wire and border zones on the SGL 33 Research and Demonstration Area. We noted the presence of plant species from late May through mid-August in both 2003 and 2004 and observed 125 vascular plant species in the 15 treatment units. The total number of species per unit ranged from a low of 35 species in a mowing unit to a high of 63 species in a basal low-volume spray unit. Of the total number of plant species found on the right-of-way, 95 (76%) and 110 (88%) occurred in wire and border zones, respectively. In wire zones, the average number of plant species ranged from 31 in mowing units to 41 in stem­foliage spray units. In border zones, the average number of plant species varied from a low of 34 in mowing units to a high of 41 in handcut units. The proportion of exotic species did not vary appreciably between wire and border zones (19% and 22% of total, respectively) on the ROW. However, the three units adjacent to unpaved state forest roads with high rates vehicular traffic not only had the highest number of total species in the unit (55 to 63 species) but also the highest number of exotic species (13 to 16 species). Hence, vehicular traffic and roadside management may be responsible in part for the invasion of seeds or other means of plant dispersal to these units. Because units relatively isolated from state forest roads tended to have fewer exotic species, these sections of the ROW can serve as refugia for native flora.

Integrated Vegetation Management On An Electric Transmission Right-Of-Way In Pennsylvania, U.S.

Integrated vegetation management (IVM) has been used for the maintenance of vegetation along an electric utility transmission right-of-way (ROW) at the State Game Lands (SGL 33) Research and Demonstration Area, Centre County, Pennsylvania, U.S., since 1987. In addition, the wire­border zone method was implemented on the ROW in 1987. The wire­border zone method results in forb­grass­shrub cover types in wire zones and shrub cover types in border zones. The SGL 33 Research and Demonstration Area has been studied since 1953, which makes this 51-year-old project the longest continuous study documenting the effects of mechanical and herbicidal maintenance on flora and fauna along an electric transmission ROW. In this paper, our objective is to present target (undesirable) tree density and cover-type development in response to IVM prior to the most recent treatment (2000) and 2 to 3 years after treatment. Results were compared to those obtained from the late 1980s and 1990s. For all units combined (except handcut) in 1999, average target tree densities prior to treatment were 288 trees/ha (117 trees/ac) in wire zones and 759 trees/ha (307 trees/ac) in border zones. Excellent control of target tree density [62 to 124 trees/ha (25 to 50 trees/ac)] was noted in wire zones of mowing plus herbicide, stem­foliage spray, and foliage spray units; moderate control [371 to 680 trees/ha (150 to 275 trees/ac)] was observed in low-volume basal spray, high-volume basal spray units, and mowing units; and poor control (4,818 trees/ha [1,951 trees/ac]) was found in the handcut unit. In 2003, the density of target trees in all treatment units combined was 1,544 trees/ha (625 tree/ac) in wire zones and 1,594 trees/ha (645 trees/ac) in border zones. If the handcut unit was omitted from the calculations, then only 340 target trees/ha (138 trees/ac) in wire zones and 501 trees/ha (203 trees/ac) in border zones were present. IVM of a ROW is not a "tree-proof" but rather a "tree-resistant" means of reducing tree invasion. Competition with existing plants and wildlife predation on tree seeds on a ROW managed via the wire­border zone method minimized but did not eliminate tree invasion. Since 1987, IVM and the wire­border zone method of ROW maintenance has increased the time between treatment cycles, thereby reducing labor and chemical costs at the SGL 33 Research and Demonstration Area.

Bird Populations Associated with an Electric Transmission Right-of-Way

A 2-year study of bird populations was conducted along a 230-kV transmission line right-of-way (ROW) in spring (June) and summer (August) 2000 and 2001. Forty-four species were observed on the ROW during 2000 and 2001. In 1987 and 1988 combined, 39 species were noted on the ROW; thus, bird populations have changed relatively little over the past 13 to 14 years. In both 2000 and 2001, slightly more species occurred on the ROW in summer (n = 26-32) than in spring (n = 25-26), and considerably fewer species were noted in the adjacent forest in both spring (n = 8-13) and summer (n = 7). Common bird species (50 individuals/100 ha/day) on the ROW were those adapted to brushy or early successional habitat. Most species were found in the low-volume basal spray and foliage spray units (n = 29 and 28 species, respectively), and fewest species were noted in the handcutting unit (n = 19 species). Considerably more bird species were observed in border zones than in wire zones of the ROW in 2000 and 2001 combined (n = 39 versus 17 species, respectively). Moreover, abundance of all bird species combined was nearly fourfold higher in border zones (1,530 individual birds/100 ha/day) than in wire zones (393 birds/100 ha/day). Thus, the border zone is a very important habitat for birds along a ROW, with its combination of shrub-forb-grass cover type.

Response of Amphibian and Reptile Populations to Vegetation Maintenance of an Electric Transmission Line Right-Of-Way

A 2-year study of amphibian and reptile populations was conducted on a 500-kV transmission line right-of-way (ROW) of PECO Energy in the Piedmont Physiographic Province, Montgomery County, Pennsylvania, U.S., from June through July 1999, September through October 1999, and March through October 2000. The objectives were to compare the diversity and relative abundance of amphibians and reptiles between the ROW and the adjacent forest, among five treatment units on the ROW, and between wire and borders zones on treatments on the ROW. Eight species were observed during the study, and the two most common species were Jefferson salamanders (Ambystoma jeffersonianum) and redback salamanders (Plethodon tinereus). All eight species were noted on the ROW, but only Jefferson and redback salamanders occurred in the adjacent forest. The number of species ranged from six species in the mowing plus herbicide unit to three each in the stem—foliage spray and foliage spray units. All species were found in the wire zones compared to only five species in the border zones. The ROW contained a greater diversity of amphibian and reptile species than the adjacent forest. Because forest-management practices can have negative impacts on populations of amphibians and reptiles, this study provides valuable information on forest-management practices required for the conservation of amphibians and reptiles.

Effect of Herbicide Maintenance of an Electric Transmission Line Right-Of-Way on Butterfly Populations

A study was carried out in 1997 of the butterfly populations on the right-of-way of a 230-kV transmission line of GPU Energy in the Allegheny Mountain Physiographic Province of central Pennsylvania. The objective was to determine if herbicide spray maintenance had produced an adverse impact on butterfly populations. Butterfly counts were made at 7 points in time during the growing season to coincide with flowering of important plant species. On the handcut control unit, there was a total of 14 butterfly species and 58 individuals present over the growing season. In contrast to this, there was a total of 20 butterfly species present on the high-volume basal spray unit, 19 species on the mowing plus herbicide spray unit MH-1, and 22 species on the mowing plus herbicide spray unit MH-3. The number of individual butterflies ranged from 172 to 186 on the 2 mowing plus herbicide spray units to 342 on the high-volume basal spray unit. These results indicate that herbicide spray maintenance had not produced an adverse effect on butterfly species and number of individuals compared to handcutting without herbicides.

Pepper-Spray-induced Respiratory Failure Treated With Extracorporeal Membrane Oxygenation

Self-defense sprays have been available to the general public since the 1970s. They are easily obtained and over 6 million spray units were sold in the United States in 1993 alone. The intent of these sprays is to cause skin and mucosal irritation without producing serious injury. We describe the accidental exposure to pepper-gas spray of an infant who experienced immediate life-threatening respiratory distress followed by progressive deterioration. Ultimately, he required extracorporeal membrane oxygenation (ECMO) for survival. The decision to place the infant on ECMO was made more difficult by the lack of information about potential reversibility with this rare toxic cause of respiratory failure.

Spray cultivation of seaweeds in recirculating brackish water

We have cultivated two species of brackish macroalgae and five Swedish and three New Zealand species of marine macroalgae. A new type of seawater spray method was developed and evaluated in a pilot-scale greenhouse on the small island of Furillen off Gotland in Sweden. Three tiers of netting were used, the seawater was recirculated and the salinity was adjusted to allow the cultivation of truly marine algae. Technically, the system worked well, achieving uniform distribution of water without clogging. Specimens tested grew well, although with low to moderate growth rates. The growth of epiphytes was limited, both on the algae and on the spray units. The macroalgae that are best suited to spray cultivation are those which are sufficiently rigid and buoyant to lie free on the net without retaining large amounts of water.

Power Plant Spray Cooling: Design and Performance Studies

A new three-dimensional model for determining the flow and thermal characteristics of spray units is utilized in an effort to predict and improve the cooling efficiency of spray units. In a marked departure from present theories, which are based on the behavior of an average droplet in a uniform average environment, the model examines the local variation in properties of both the air and the droplets throughout the flow field encompassing the spray umbrella. Model predictions of droplet return temperature along the spray perimeter, downwind wet-bulb temperature, and downwind air-velocity were compared with field data on a commercial spray. Good agreement was observed. A parametric study was then performed to determine the optimum droplet size and discharge angle for a spray unit. It was found that substantial improvements in the cooling obtained for a given spray power input can be achieved over currently used floating spray units.

Performance of Power Plant Spray Cooling Modules and Systems

The detailed three-dimensional local interaction model developed previously for spray units is used here to predict the cooling performance of both a pass of sprays coaxially aligned with the wind, and a multipass spray system. Since the model predicts the local changes in temperature and humidity of the air-vapor phase as well as droplet trajectories and temperatures, it is capable of determining the degree of interference between adjacent spray units as a function of upwind conditions and spray spacing without recourse to empirical interference factors. Model predictions are compared with droplet cooling and wet-bulb temperature data for spray passes consisting of units of the Power Spray Module. The thermal efficiency of a pass of sprays is examined by use of a theoretically generated dimensionless performance chart.. Such charts are utilized in a computer model of a multipass spray canal system. The model shows excellent agreement with system data. System design and performance charts are presented for industrial use.

Characterization of Dose Delivery and Spray Pattern of a Metered-Dose Flunisolide Nasal Spray

AbstractFlunisolide is a synthetic fluorinated corticosteroid with significant ant -inflammatory and anti-allergic activities. Flunisolide nasal solution (Nasalide®) is delivered by a unique pump-activated, non-propellant, metered-dose device. A previous paper (1) reported droplet size characterization of the nasal spray by a cascade impactor. This report describes the remaining physical characterizations, namely dose delivery and spray pattern, of this metered-dose delivery system as well as the suitability of the system for a therapeutic corticosteroid nasal solution.Actuation of flunisolide nasal spray units by 10 subjects over time demonstrated good constancy of dose delivery for up to 24 days of use. The average dose delivery was 0.737 ± 0.040 gm/day (grand mean ± s.d.).Actuation of similar units by 17 subjects over time showed good constancy of spray pattern, which was defined as the long and short diameters of the impaction pattern of the spray on a TLC plate, for the entire lifetime of the unit.

Pesticide applicator exposure to insecticides during treatment of citrus trees with oscillating boom and airblast units

To obtain relative exposure data for the spray rig driver applying insecticides to California citrus trees, parathion [O,O-diethylO-(4-nitrophenyl) phosphorothioate] and dimethoate [O,O dimethylS-(2-(methylamino)-2-oxoethyl) phosphorodithioate] were applied with oscillating boom and airblast spray units. Spraying conditions were varied to simulate commercial application practices. Test conditions were used which varied from providing no driver protection to that of providing charcoal-filtered air. Both singleand double-side delivery systems were employed. Gauze sponges pinned to the coveralls of the driver were used to indicate dermal exposure potential, and ethylene glycol-containing impinger type air samplers were used to indicate inhalation exposure potential. Urine samples were collected and analyzed for dialkylphosphate and thiophosphate levels.