scholarly journals Investigation of Oil Droplet Breakup during Atomization of Emulsions: Comparison of Pressure Swirl and Twin-Fluid Atomizers

Fluids ◽  
2021 ◽  
Vol 6 (6) ◽  
pp. 219
Author(s):  
Martha L. Taboada ◽  
Esteban Zapata ◽  
Heike P. Karbstein ◽  
Volker Gaukel
Keyword(s):  
Droplet Size ◽  
Volume Flow ◽  
Droplet Breakup ◽  
Spray Droplet ◽  
Flow Rates ◽  
Oil Droplet ◽  
Droplet Sizes ◽  
Pressure Swirl ◽  
Oil Droplet Size ◽  
Nozzle Type

The goal of this study was to investigate oil droplet breakup in food emulsions during atomization with pressure swirl (PS), internal mixing (IM), and external mixing (EM) twin-fluid atomizers. By this, new knowledge is provided that facilitates the design of atomization processes, taking into account atomization performance as well as product characteristics (oil droplet size). Atomization experiments were performed in pilot plant scale at liquid volume flow rates of 21.8, 28.0, and 33.3 L/h. Corresponding liquid pressures in the range of 50–200 bar and air-to-liquid ratios in the range of 0.03–0.5 were applied. Two approaches were followed: oil droplet breakup was initially compared for conditions by which the same spray droplet sizes were achieved at constant liquid throughput. For all volume flow rates, the strongest oil droplet breakup was obtained with the PS nozzle, followed by the IM and the EM twin-fluid atomizer. In a second approach, the concept of energy density EV was used to characterize the sizes of resulting spray droplets and of the dispersed oil droplets in the spray. For all nozzles, Sauter mean diameters of spray and oil droplets showed a power-law dependency on EV. PS nozzles achieved the smallest spray droplet sizes and the strongest oil droplet breakup for a constant EV. In twin-fluid atomizers, the nozzle type (IM or EM) has a significant influence on the resulting oil droplet size, even when the resulting spray droplet size is independent of this nozzle type. Overall, it was shown that the proposed concept of EV allows formulating process functions that simplify the design of atomization processes regarding both spray and oil droplet sizes.

scholarly journals Breakup and Coalescence of Oil Droplets in Protein-Stabilized Emulsions During the Atomization and the Drying Step of a Spray Drying Process

2021 ◽  
Author(s):  
Martha L. Taboada ◽  
Doll Chutani ◽  
Heike P. Karbstein ◽  
Volker Gaukel
Keyword(s):  
Spray Drying ◽  
Droplet Size ◽  
Concentration Ratio ◽  
Oil Content ◽  
Droplet Breakup ◽  
Drying Process ◽  
Oil Droplets ◽  
Oil Droplet ◽  
Oil Concentration ◽  
Oil Droplet Size

AbstractThe goal of this study was to investigate the changes in oil droplet size in whey protein–stabilized emulsions during the atomization and the subsequent drying step of a spray drying process. For this purpose, experiments were performed in an atomization rig and a pilot spray dryer with two commercial pressure swirl atomizers. By comparing the oil droplet size before atomization, after atomization, and after spray drying, the changes in oil droplet size during each process step were quantified. The effect of oil droplet breakup during atomization was isolated by atomizing emulsions with 1 wt.% oil content and a protein to oil concentration ratio of 0.1. At 100 bar, the Sauter mean diameter of oil droplet size was reduced from 3.13 to 0.61 μm. Directly after breakup, coalescence of the oil droplets was observed for emulsions with a high oil content of 30 wt.%, leading to a droplet size after atomization of 1.15 μm. Increasing the protein to oil concentration ratio to 0.2 reduced coalescence during atomization and oil droplets with a mean diameter of 0.92 μm were obtained. Further coalescence was observed during the drying step: for an oil content of 30 wt.% and a protein to oil concentration ratio of 0.1 the mean droplet size increased to 1.77 μm. Powders produced at high oil contents showed a strong tendency to clump. Comparable effects were observed for a spray drying process with a different nozzle at 250 bar. The results confirm that droplet breakup and coalescence during atomization and coalescence during drying have to be taken into consideration when targeting specific oil droplet sizes in the product. This is relevant for product design in spray drying applications, in which the oil droplet size in the powder or after its redispersion determines product quality and stability.

Effects of Varying Liquid Fuel and Air Co-Flow Rates on Spray Characterisation of an Annular Co-Flow Spray Burner

2019 ◽  
Author(s):  
R. A. Alsulami ◽  
S. Nates ◽  
W. Wang ◽  
S. H. Won ◽  
Bret Windom
Keyword(s):  
Size Distribution ◽  
Droplet Size ◽  
Liquid Fuel ◽  
Air Flow ◽  
Droplet Size Distribution ◽  
Droplet Breakup ◽  
Flame Stability ◽  
Flow Rates ◽  
Droplet Sizes ◽  
The Impact

Abstract Development of efficient and clean combustion systems requires the understanding of all the processes experienced by a complex liquid fuel in IC engines, such as atomization, vaporization, turbulent mixing, and combustion. Many of these processes are interconnected; the atomization process, which leads to various droplet sizes can enhance or diminish the vaporization rate of the liquid fuel and consequently impact the energy conversion process. Furthermore, the combustion/flame stability of liquid-fueled gas turbine can be influenced by the fuel and the air co-flow rates delivered in the engine. Increasing the fuel and/or air flow rates can enhance droplet breakup and the turbulence of the flow, and as a result sway the droplet size distribution of the spray. This work focuses on investigating the impact of varying the fuel and air flow rates on the spray atomization (e.g. droplet size distribution) of an Annular Co-Flow Spray Burner. This was explored by measuring droplet sizes and velocities of the spray at different radial and axial positions of n-heptane fuel under nonreacting conditions. In addition, the turbulence intensity and the liquid spray droplet distribution were quantified for different fuel and air flow rate conditions. The measurements were obtained by using a Phase Doppler Particle Analyzer/Laser Doppler Velocimeter (PDPA/LDV) at P = 1 atm and T = 298 K. Moreover, the Sauter Mean Diameters for different flow conditions are predicted, using an established correlations, and compared to PDPA/LDV measurements. The results provided a fair understanding of the influence of varying the fuel and air flow rates on the droplet sizes, velocity, and turbulent intensity. Furthermore, the results presented here will support future work that will focus on unraveling the role of phase change on flame stability.

scholarly journals Effect of storage on the rheological and viscoelastic properties of mayonnaise emulsions of different oil droplet size

Heliyon ◽  
2020 ◽  
Vol 6 (12) ◽  
pp. e05788
Author(s):  
George Katsaros ◽  
Magdalini Tsoukala ◽  
Marianna Giannoglou ◽  
Petros Taoukis
Keyword(s):  
Droplet Size ◽  
Viscoelastic Properties ◽  
Oil Droplet ◽  
Oil Droplet Size

scholarly journals Effect of Polydispersity in Oil-droplet Size on Lipid Oxidation in Oil-in-water Emulsions

2016 ◽  
Vol 17 (3) ◽  
pp. 91-94 ◽  
Author(s):  
Yayoi MIYAGAWA ◽  
Kohshi KIKUCHI ◽  
Hirokazu SHIGA ◽  
Shuji ADACHI
Keyword(s):  
Lipid Oxidation ◽  
Droplet Size ◽  
Oil Droplet ◽  
Oil In Water ◽  
Oil Droplet Size

Droplet size impact on lactofen and acifluorfen efficacy for Palmer amaranth (Amaranthus palmeri) control

2019 ◽  
Vol 34 (3) ◽  
pp. 416-423
Author(s):  
Lucas X. Franca ◽  
Darrin M. Dodds ◽  
Thomas R. Butts ◽  
Greg R. Kruger ◽  
Daniel B. Reynolds ◽  
...  
Keyword(s):  
Droplet Size ◽  
Pulse Width Modulation ◽  
Effective Means ◽  
Cost Effective ◽  
Palmer Amaranth ◽  
Target Movement ◽  
Spray Droplet ◽  
Spray Droplets ◽  
Droplet Sizes ◽  
Biomass Reduction

AbstractHerbicide applications performed with pulse width modulation (PWM) sprayers to deliver specific spray droplet sizes could maintain product efficacy, minimize potential off-target movement, and increase flexibility in field operations. Given the continuous expansion of herbicide-resistant Palmer amaranth populations across the southern and midwestern United States, efficacious and cost-effective means of application are needed to maximize Palmer amaranth control. Experiments were conducted in two locations in Mississippi (2016, 2017, and 2018) and one location in Nebraska (2016 and 2017) for a total of 7 site-years. The objective of this study was to evaluate the influence of a range of spray droplet sizes [150 (Fine) to 900 μm (Ultra Coarse)] on lactofen and acifluorfen efficacy for Palmer amaranth control. The results of this research indicated that spray droplet size did not influence lactofen efficacy on Palmer amaranth. Palmer amaranth control and percent dry-biomass reduction remained consistent with lactofen applied within the aforementioned droplet size range. Therefore, larger spray droplets should be used as part of a drift mitigation approach. In contrast, acifluorfen application with 300-μm (Medium) spray droplets provided the greatest Palmer amaranth control. Although percent biomass reduction was numerically greater with 300-μm (Medium) droplets, results did not differ with respect to spray droplet size, possibly as a result of initial plant injury, causing weight loss, followed by regrowth. Overall, 900-μm (Ultra Coarse) droplets could be used effectively without compromising lactofen efficacy on Palmer amaranth, and 300-μm (Medium) droplets should be used to achieve maximum Palmer amaranth control with acifluorfen.

Effect of Formulation and Nozzle Type on Droplet Size with Isopropylamine and Trimesium Salts of Glyphosate

1997 ◽  
Vol 11 (4) ◽  
pp. 639-643 ◽  
Author(s):  
Thomas C. Mueller ◽  
Alvin R. Womac
Keyword(s):  
Nonionic Surfactant ◽  
Weed Control ◽  
Droplet Size ◽  
Management Tool ◽  
Spray Droplet ◽  
Droplet Distribution ◽  
Extended Range ◽  
Glyphosate Formulation ◽  
Nozzle Type ◽  
Flat Fan Nozzle

When spray mixtures were examined using a laser spray droplet analyzer, the new isopropylamine glyphosate formulation produced more small droplets than a previous isopropylamine salt of glyphosate formulation or glyphosate–trimesium plus nonionic surfactant. The use of a pre-orifice flat-fan nozzle and an impact type flat-fan nozzle reduced the amount of small droplets produced compared to an existing extended range flat-fan nozzle, while maintaining a spray droplet distribution that could still provide good weed control. The new nozzle technologies could provide a useful management tool to manage potential drift situations.

Effect of protein type, concentration and oil droplet size on the formation of repulsively jammed elastic nanoemulsion gels

Soft Matter ◽  
2019 ◽  
Vol 15 (47) ◽  
pp. 9762-9775 ◽  
Author(s):  
Aakash Patel ◽  
Athira Mohanan ◽  
Supratim Ghosh
Keyword(s):  
Whey Protein ◽  
Droplet Size ◽  
Sodium Caseinate ◽  
Oil Droplet ◽  
Critical Droplet ◽  
Oil In Water ◽  
Oil Droplet Size

Sodium caseinate (SC)-stabilized 40% oil-in-water nanoemulsions (NEs) could be transformed into elastic gels below a critical droplet size due to increase in ϕeff by a thicker steric barrier of SC, while whey protein (WPI)-stabilized NEs remained liquid due to thinner steric barrier of WPI.

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