Solid-cone Nozzles Research Articles

An Experimental Investigation of the Impact of Surface Tension and Viscosity on the Atomization Effect of a Solid Cone Nozzle

To investigate the influence of surface tension and viscosity on the atomization performance of solid cone nozzles and improve their dust reduction efficiency in industrial and mining enterprises, this study employed a self-built PDPA dust-fog coupling experimental system to explore the effects of different surface tension and viscosity solutions on atomization performance from three aspects: axial, radial, and fog field distribution. The experimental results indicate that compared with surface tension, surface tension has a greater influence on droplet size and velocity in the axial direction. In the radial direction, increasing surface tension and reducing viscosity within a certain range can make the droplet size and velocity distribution more uniform. Additionally, surface tension and viscosity significantly affect the fog field distribution. It was found that a decrease in surface tension can result in a closer proximity of the droplet velocity and size expansion area to the nozzle, while an increase in viscosity can lead to a more prolonged stable area. Furthermore, optimizing the surface tension and viscosity can significantly enhance the efficacy of dust reduction for respirable dust. Consequently, the application of the aforementioned atomization principles to regulate the fog field characteristics of solid cone nozzles can effectively mitigate dust in the production process and augment the dust reduction rate of industrial and mining enterprises.

Study on water spraying distribution to improve the energy recovery performance of indirect evaporative coolers with nozzle arrangement optimization

In response to the worldwide call for energy conservation and carbon emission reduction, indirect evaporative cooling as a green and environmentally friendly technology has been extensively researched and developed. In the practical application of this technology, the spray nozzle arrangement results in different wettability factors of the wet channel surface, which accordingly has a significant impact on its cooling efficiency. Existing research has discussed indirect evaporative coolers (IECs) in various external shapes, internal configurations, and materials. However, the IEC performance improvement was rarely analyzed from the perspective of the spray nozzle arrangement. This paper developed and validated a numerical model to predict the spray water density distribution of the solid cone nozzles on the impact surface with uniformly divided square grids. The actual water spray density obtained from this model could then be used to correct the wetting factor in the existing IEC numerical model. The control variable method was applied to compare the effect of inclined angle and distance between the nozzles. According to the uniformity coefficient as well as coverage ratio of the water spray, the optimal arrangement scheme, i.e. the nozzles mounted along the centerline with the distance of 160 mm, was determined. Results showed that a uniform coefficient of 0.74 can be obtained in the optimal distribution of the full cone nozzle. Greater air cooling and dehumidification were achieved by the optimized nozzle arrangement scheme compared with the original single-line arrangement scheme of the nozzles. The coefficient of performance (COP) of the IEC system could be increased by 16% under the same operating conditions when the optimized spray nozzle arrangement was adopted, which indicated the benefit and importance of the IEC spray nozzle arrangement optimization.

Efficacy of Organically Acceptable Insecticides AgainstDrosophila suzukii(Diptera: Drosophilidae) in Blueberries, 2014

The efficacy of two unregistered organically acceptable insecticides on SWD was assessed in June and July, 2014. The experiment was conducted at the Horticultural Crops Research Station near Castle Hayne, NC in a planting of rabbiteye blueberries, var. Premier. Treatments were replicated four times and arranged in an RCB design, blocked by rows, with a one-row buffer in between blocks. Plots consisted of five plants, 0.00415 acres, each. The following four treatments were compared: untreated control (UTC), Veratran D, Ecotec + TriTek, and Entrust SC (Table 1). Following label recommendations, Entrust was tank mixed with a nonionic surfactant, Dyne-Amic. Treatments were applied on 23 June using a CO2 pressurized backpack sprayer fitted with three solid cone nozzles (TeeJet TG 5 with medium size filter) calibrated to deliver a spray volume of 50 gpa at 45 psi pressure. Due to issues with the filter clogging during the Veratran D application, the following adjustments …

Efficacy of Insecticides AgainstDrosophila suzukii(Diptera: Drosophilidae) in Blueberries, 2014

The efficacy of formulation of malathion currently unregistered in blueberries, Atrapa, was compared with a standard malathion formulation and a recently registered material, Exirel for efficacy against SWD in May and June, 2014. Exirel treatments were compared with and without a surfactant. This experiment was conducted at the Horticultural Crops Research Station near Castle Hayne, NC in a planting of southern highbush blueberries, var. “Legacy.” Plots were 0.05 acres each and consisted of two rows of five plants. Treatments were replicated four times and arranged in an RCB design, blocked by rows, with a one-row untreated buffer in between blocks. Treatments (Table 1) were applied using a CO2 pressurized backpack sprayer fitted with three solid cone nozzles (TeeJet TG 5 with medium size filter) calibrated to deliver a spray volume of 50 gpa at 45 psi pressure. Both sides of a row were treated to ensure full plant …

New mechanized system for circle spraying of oil palms seedling emergence

A new machine system has been designed, developed and evaluated for extensive circle spraying of oil palms (Elaeis guineensis Jacq.) in an effort to overcome the inefficient spraying problem with the conventional spraying system. The machine system consists of a four-wheeled drive 4WD prime mover with front mounted machine attachments for the circle spraying operation. The configuration of the circle spraying attachment consists of a hexagonal curved spray boom, lifting arm, opening-tilting mechanism unit, storage tank, spray pump, solid cone nozzles, and associate hydraulic system. Field performance tests on the machine system showed an average effective field capacity of 7.89 ha per man per day and when compared to the earlier reported effective field capacity of the walking spray-operated equipment using Serena LT16 knapsack sprayer; a difference of 1.97 time for circle spraying of mature palms grove. Reduction in the human energy expenditure of 101.28 kJ man-1 h-1 or 10.68 % but an increase in the spraying cost of 1.53 USD ha-1 or 24.9 % were obtained with the machine system against the walking spraying-operated equipment using Serena LT16 knapsack sprayer. Justification for machine system to be cost effective could be satisfied if the present effective field capacity is increased to 1.263 time with good skilled operator or if the current R&D cost is reduced to 0.41 time. This is because the improved field capacity of new machine system could not rationalize its current R&D cost. Admittedly, the machine system has great potential to overcome the limitations with the current employed machine/equipment in the circle spraying operation of oil palms in the plantation.

Mechanised Weed Control Applicator for Mature Oil Palm

A new machine system has been designed, developed and evaluated for extensive weed control around mature oil palm. The machine system consists of a 4WD prime mover with the front mounted machine attachments for circle spraying operation. The configuration of the circle spraying attachment consists of the hexagonal curved spray boom, lifting arm, opening-tilting mechanism unit, storage tank, spray pump, solid cone nozzles, and associate hydraulic system. Field performance tests on the machine system showed an average effective field capacity of 7.89 ha per manday and when compared against the earlier reported effective field capacity of the walking spray-operated equipment using rechargeable battery powered knapsack sprayer, there was a difference of 1.97 times for circle spraying of mature palms grove. A reduction in the human energy expenditure of 24.19 kcal per manhour or 10.68 per cent but an increase in the spraying cost per hectare of USDl.53 per hectare (RM4.66/ha) or 24.9 per cent were obtained with the machine system against the walking spraying-operated equipment using rechargeable battery powered knapsack sprayer. Justification for machine system to be cost effective could be satisfied if the present effective field capacity is increased to 26.3 per cent with a good skilled operator or if the current R&D cost is reduced to 0.41 times. This is because the improved field capacity of the new machine system could not rationalise its current R&D cost. Admittedly, the machine system has great potential to overcome the limitations with the currently employed machine/equipment in the circle spraying operation of oil palm in the plantation. Keywords: Circle spraying, oil palm cultivation, agricultural machinery, mechanisation.

Droplet size and spray pattern characteristics of PWM-based continuously variable spray

A Pulse-Width-Modulation-based (PWM-based) continuously variable sprayer was developed using a proportional regulating solenoid valve. Variable flow-rate was obtained by varying the duty cycle of the actuating signal with 24 kHz frequency. Flow-rate regulating ranges of the PWM-based continuously variable spray (i.e. the turndown ratio responding to 100%-40% duty cycle) are 7.14:1, 3.57:1, and 3.70:1 for flat-fan, hollow-cone and solid-cone nozzles, respectively. The purpose of the study was to evaluate the PWM-based continuously variable spray. The method was to quantify the effects of flow-rate control on spray characteristics in terms of droplet size spectra, spray distribution patterns, and spray angle for flat-fan, hollow-cone, solid-cone nozzles. For all nozzles tested, spray distribution concentrated on the center of the spray field with the decrease of flow-rate. But the spray shape is still symmetrical. The sensitivities of the spray angles to flow-rate were 0.83, 0.67, and 0.58 (o)/% respectively for flat-fan, hollow-cone and solid-cone nozzles. Compared with the sensitivities of spray angle for PWM-based intermittent variable spray, they are somewhat larger. As flow-rate was reduced from the maximum (100% flow-rate) to the minimum controllable rate, the observed median diameter of spray droplets decreased by 5.4%, 9.8%, and 9.9 % for flat-fan, hollow-cone and solid-cone nozzles, respectively. This indicates that spray droplet size was affected slightly by flow-rate control. Keywords: Pulse Width Modulation (PWM), continuously variable spray, droplet size, spray distribution pattern, spray angle DOI: 10.3965/j.issn.1934-6344.2009.01.008-018 Citation: Deng Wei, He Xiongkui, Ding Weimin. Droplet size and spray pattern characteristics of PWM-based continuously variable spray. Int J Agric & Biol Eng, 2009; 2(1): 8

Entrainment from Spray Distributors for Packed Columns

Spray nozzles are widely used to provide a uniform liquid distribution to packed distillation and absorption columns. A disadvantage of such distributors is, however, the tendency for the atomized drops to be entrained by the upflowing gas. In some instances it is not convenient or even possible to remove the entrained liquid from the gas. A theoretical model has been developed for estimating the total entrainment from spray nozzle distributors. The model is based on drop size distribution and drop bouyancy relationships and has been confirmed by measurements in a 11.5-in. diameter spray contactor, using four different solid-cone nozzles and the air−water system. The model has also been confirmed by measurements of others using an air−paraffinic oil system. The model takes into account orifice diameter, phase flow rates, and phase physical properties. It predicts total entrainment and does not allow for partial removal of entrainment by walls, adjacent sprays, or target devices used to collect the entrained liquid. Thus, the predictions are conservative for multiple spray nozzle assemblies.

Tobacco Budworm Control on Flue-Cured Tobacco with Foliar Insecticides, 1996

Abstract Flue-cured tobacco was planted on the James T. Smith farm in Wayne Co., NC on 23 Apr. Plots of 0.02 acre (4 rows X 57 ft) were separated laterally by a vacant 5th row and on each end by turn alleys of 16 ft. Treatments were established in a RCB design with 4 replications. Just prior to treatment, a moderate natural infestation of budworms was augmented by artificial infestation of 10 plants in each of the 1st and 3rd rows of each plot. A single 2-d old larva (from the colony maintained by the Dept. of Entomology, N.C. State University) was transferred from artificial diet to each plant. Larvae were placed into the bud to simulate an established infestation. Treatments were applied on 3 Jun using a tractor-mounted sprayer (with the exception of Dipel 10 G) pressurized by a roller pump powered by the tractor PTO. Spray was delivered through 3 solid-cone nozzles (TG-1, TG-2, TG-1) per row at 60 psi and 37.5 gpa. Treatments were applied between 2:50 pm and 5:00 pm EDT. Diatect was treated as a wettable powder and sprayed. Dipel 10G was applied by hand directly to the bud of each plant. Air temperature was approximately 80° F and winds were light to moderate (3-7 mph). All plants (excluding the first and last) in rows 1 and 3 were checked for budworm infestation on the day of treatment and 4 and 11 DAT. These plants were rated for budworm damage 15 DAT. Individual plants were examined and an estimate of leaf area lost to budworm feeding made. Damage was scored as follows: 0 = no damage; 1 = less than 1.0 leaf equivalent lost; 2 = 1.0 - 2.0 leaf equivalents; 3 = more than 2.0 leaf equivalents lost; 4 = plant topped by budworm feeding. Average damage ratings were calculated by plot. After harvest and curing, tobacco from each plot was weighed and graded by a government grader. Grades were converted to a quality index (1-100, 100 high). All variables were subjected to analysis of variance and treatment means compared (where appropriate) using an LSD test. Before analysis, the proportion of plants infested was transformed to the arcsine of square root of proportion. Data shown in the table are not transformed and proportion of plants infested is presented as percentage of plants infested.

Control of Spider Mites on Cotton, 1981

Abstract Acaracides were applied to Acala SJ-2 cotton planted Apr 5 near Five Points, CA in rows spaced at 40 inches. Individual plots were 8 rows wide and 100 ft long. Treatments were replicated 6 times in a randomized complete block design and applied Jul 14. On Aug 28 Mitac was reapplied to the 0.25 + 0.25 lb ai/acre treatment. Applications were made by high clearance sprayer equipped with drop booms using 5 solid cone nozzles per row delivering 47 gal/acre at 40 psi. Mainstem leaves (fifth unfolded leaf below mainstem terminal) were sampled on 4 post-treatment dates and processed through a sodium hypochlorite wash system. Counts were made of all active stages of the Tetranychid complex; only adult female counts are reported as they represent a consistent proportion of the total population. Mite counts were transformed by x + 0.5 for statistical analysis. Yield was determined by mechanically harvesting the 4 center rows of each plot on Oct 9.

Control of Spider Mites on Cotton, 1981

Abstract Acaracides were applied to Acala SJ-2 cotton planted Apr 18 near Shatter, CA in 40 inch rows. Individual plots were 8 rows wide and 70 ft long. Treatments were replicated 4 times in a randomized complete block design and applied Jun 29. On Jul 21 both formulations of PIictran and Mitac at both rates were reapplied. Applications were made by high clearance sprayer equipped with drop booms using 5 solid cone nozzles per row delivering 47 gal/acre at 40 psi. Mainstem leaves (fifth unfolded leaf below mainstem terminal) were sampled on 5 post-treatment dates and processed through a sodium hypochlorite wash system. Counts were made of all active stages of the Tetranychid complex; only adult female counts are reported as they represent a consistent proportion of the total population. Mite counts were transformed by x + 0.5 for statistical analysis. Yield was determined by mechanically harvesting the 4 center rows of each plot on Oct 22.

Control of Spider Mites on Cotton, 1981

Abstract Acaracides were applied to Acala SJ-2 cotton planted Apr 5 near Five Points, CA, in rows spaced at 40 inches. Individual plots were 8 rows wide and 100 ft long. Treatments were replicated 3 times in a randomized complete block design and applied Aug 13. Applications were made by high clearance sprayer equipped with drop booms using 5 solid cone nozzles per row delivering 47 gal/acre at 40 psi. Mainstem leaves (fifth unfolded leaf below mainstem terminal) were sampled on 3 post-treatment dates and processed through a sodium hypochlorite wash system. Counts were made of adult females of the Tetranychid complex as they represent a consistent proportion of the total population. Mite counts were transformed by x + 0.5 for statistical analysis.

Green Peach Aphid and Tobacco Flea Beetle Control on Flue-Cured Tobacco, 1981

Abstract ‘McNair 944’ flue-cured tobacco was transplanted in 4 ft rows with 20 inch row spacing on May 12. Treatment plots, 20 ft (12 plants) x 4 ft (1 row), were separated on each side by untreated border rows and they were arranged in a randomized complete block design replicated 5 times. Treatments were applied with a CO2 powered back-pack sprayer, 3 nozzles/row, 60 gal/acre, 60 psi and TG-3 solid cone nozzles in Jul. Four of the insecticides tested were applied alone and in combination with Ortho X77 spreader sticker at 0.5 pt/acre. Green peach aphids were counted on 2 upper leaves (ca 18 inches long) of 5 plants/plot, at 1 day pre-treatment and 3 and 12 days post-treatment. Tobacco flea beetles were counted on 5 plants/plot at 12 days post-treatment.

Use of the starwheel sprayer for applying drying emulsion to sultana grapes to be dried on the trellis

The development of the starwheel sprayer for the application of drying emulsion to Sultanas is described. This sprayer consists, in its standard form, of three sets of six radially and horizontally arranged spokes. Each spoke is fitted with three wide angle, solid cone nozzles which spray near and inside the vine canopy. Spraying vines with the starwheel sprayer took one tenth of the time needed to spray the fruit to saturation by hand. Experiments indicated that at least 4000 l ha-1 of spray emulsion containing at least 1.5 per cent oil and 1.875 per cent K2CO3 were needed to obtain sufficient coverage of the fruit for an adequate rate of drying and to ensure good quality of the fruit. The colour of dried sultanas produced by trellis drying after spraying with the starwheel sprayer was darker and less uniform than the colour of fruit produced by rack-spraying and -drying. This appeared to be related to the system of trellis-drying in general rather than to the use of the starwheel sprayer. It is concluded that the starwheel sprayer successfully meets the requirements for applying drying emulsion to Sultanas to be dried on the trellis.