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.

scholarly journals Effect of oil droplet size on activation energy for coalescence of oil droplets in an O/W emulsion

2015 ◽  
Vol 79 (10) ◽  
pp. 1695-1697 ◽  
Author(s):  
Yayoi Miyagawa ◽  
Kazutaka Katsuki ◽  
Ryuichi Matsuno ◽  
Shuji Adachi
Keyword(s):  
Activation Energy ◽  
Droplet Size ◽  
Oil Droplets ◽  
Oil Droplet ◽  
Oil Droplet Size

Subsea Dispersant Injection (SSDI) - Summary Findings from a Multi-Year Research and Development Industry Initiative

2017 ◽  
Vol 2017 (1) ◽  
pp. 2762-2790 ◽  
Author(s):  
P.J. Brandvik ◽  
Ø. Johansen ◽  
E.J. Davies ◽  
F. Leirvik ◽  
D.F. Krause ◽  
...  
Keyword(s):  
Water Column ◽  
Droplet Size ◽  
Oil And Gas ◽  
Two Dimensions ◽  
Worker Safety ◽  
Three Dimensions ◽  
Oil Droplets ◽  
Oil Droplet ◽  
Elevated Exposure ◽  
Oil Droplet Size

ABSTRACT New and novel results regarding effectiveness and use of subsea dispersant injection (SSDI) are presented in this paper. These findings are relevant for operational guidance, decision making and improvement of models of subsea releases of oil and gas. More specifically, the paper presents data from a comprehensive set of laboratory experiments to measure the initial formation of oil droplets and gas bubbles from a subsea blowout with and without SSDI. Many subsea blowout scenarios for oil and gas will form relatively large oil droplets (multiple millimeters) which rise rapidly through the water column to possibly form thick slicks on the ocean surface, potentially very near the source. On the other hand, smaller oil droplets (< 500 microns) rise more slowly and can stay suspended in the water column for days to weeks. Our laboratory studies examined the influence of different variables on the initial oil droplet size including oil release velocity, dispersant dosage, dispersant injection method, oil temperature, pressure, gas-to-oil ratio, oil type, and dispersant type. Results revealed that dispersant injection is highly effective at reducing droplet size. SSDI has, for this reason, a potential to reduce floating oil and associated volatile hydrocarbons that may threaten worker health and safety. Reduced surfacing may also reduce the amount of oil that reaches ecologically sensitive shoreline environments. Oil that disperses into the water column, as small droplets, may cause temporarily elevated exposure to marine organisms, but these droplets rapidly dilute and later naturally degrade. Dispersed oil dilutes in three dimensions rather than only the two dimensions available for surface oil, and mostly one dimension available to shoreline oil. Our data fit a modified Weber scaling algorithm that predicts initial oil droplet size for both laboratory and field scales. Predictions indicate that SSDI can reduce oil droplet sizes by an order of magnitude for field scales like those experienced in the Deep Water Horizon. In summary, this paper shows that SSDI applied to a subsea blowout is a highly efficient oil spill response tool that, under the appropriate conditions, can substantially delay oil surfacing, reduce the amount of surfacing and reduce the persistence of surface slicks by reducing oil droplet size. The net result is enhanced worker safety and health as well as reduced oil impacts on the surface and shoreline.

scholarly journals Media Flow Analysis of Single-Channel Pre-Mixed Liquid CO2 and MQL in Sustainable Machining

2021 ◽  
Vol 67 (1-2) ◽  
pp. 3-10
Author(s):  
Damir Grguraš ◽  
Luka Sterle ◽  
Aleš Malneršič ◽  
Luka Kastelic ◽  
Cedric Courbon ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Droplet Size ◽  
Tool Life ◽  
Single Channel ◽  
Flow Analysis ◽  
Nozzle Outlet ◽  
Oil Droplets ◽  
Oil Droplet ◽  
Cooling And Lubrication ◽  
Oil Droplet Size

Single-channel supply of pre-mixed liquid carbon dioxide (LCO2) and minimum quantity lubrication (MQL) represents a state-of-the-art LCO2 assisted machining. However, to fully understand and optimize cooling and lubrication provided by the LCO2 + MQL, a fundamental media flow analysis is essential, yet not researched enough. Therefore, in this paper, media flow velocity and oil droplet size were analysed in supplying line and at the nozzle outlet using high-speed camera and proprietary single-channel system. Results indicate that pre-mixed media flow velocity is mainly influenced by the LCO2 expansion rate upon the nozzle outlet, wherein oil droplet size is largely dependent on the solubility between oil and LCO2. Media flow velocity increases significantly from an average of 40 m/s in the supplying line to the excess of 90 m/s at the nozzle outlet due to the pressure drop and LCO2 expansion. Furthermore, this volume expansion causes the oil droplet to increase to the point of critical, unstable droplet size. Afterward, the unstable oil droplet breaks up into smaller oil droplets. It was found, that nonpolar oil, with greater solubility in LCO2, compared to the polar oil, provides droplets as small as 2 μm in diameter. Smaller oil droplets positively reflect on tool wear and tool life in LCO2 assisted machining, as the longest tool life was achieved by using the nonpolar oil for pre-mixed LCO2 + MQL.

scholarly journals Numerical Simulation of the Oil Droplet Size Distribution Considering Coalescence and Breakup in Aero-Engine Bearing Chamber

2020 ◽  
Vol 10 (16) ◽  
pp. 5648
Author(s):  
Fei Wang ◽  
Lin Wang ◽  
Guoding Chen ◽  
Donglei Zhu
Keyword(s):  
Size Distribution ◽  
Droplet Size ◽  
Mass Flow ◽  
Droplet Diameter ◽  
Droplet Size Distribution ◽  
Oil Droplets ◽  
Oil Droplet ◽  
Aero Engine ◽  
Oil Droplet Size ◽  
Engine Bearing

In order to improve the inadequacy of the current research on oil droplet size distribution in aero-engine bearing chamber, the influence of oil droplet size distribution with the oil droplets coalescence and breakup is analyzed by using the computational fluid dynamics-population balance model (CFD-PBM). The Euler–Euler equation and population balance equation are solved in Fluent software. The distribution of the gas phase velocity field and the volume fraction of different oil droplet diameter at different time are obtained in the bearing chamber. Then, the influence of different initial oil droplet diameter, air, and oil mass flow on oil droplet size distribution is discussed. The result of numerical analysis is compared with the experiment in the literature to verify the feasibility and validity. The main results provide the following conclusions. At the initial stage, the coalescence of oil droplets plays a dominant role. Then, the breakup of larger diameter oil droplet appears. Finally, the oil droplet size distribution tends to be stable. The coalescence and breakup of oil droplet increases with the initial diameter of oil droplet and the air mass flow increasing, and the oil droplet size distribution changes significantly. With the oil mass flow increasing, the coalescence and breakup of oil droplet has little change and the variation of oil droplet size distribution is not obvious.

scholarly journals Spray drying of emulsions: Influence of the emulsifier system on changes in oil droplet size during the drying step

2021 ◽  
Author(s):  
Martha L. Taboada ◽  
Theresia Heiden‐Hecht ◽  
Monika Brückner‐Gühmann ◽  
Heike P. Karbstein ◽  
Stephan Drusch ◽  
...  
Keyword(s):  
Spray Drying ◽  
Droplet Size ◽  
Oil Droplet ◽  
Emulsifier System ◽  
Oil Droplet Size

scholarly journals Influence of the Emulsifier System on Breakup and Coalescence of Oil Droplets during Atomization of Oil-In-Water Emulsions

2020 ◽  
Vol 4 (3) ◽  
pp. 47
Author(s):  
Martha Taboada ◽  
Nico Leister ◽  
Heike Karbstein ◽  
Volker Gaukel
Keyword(s):  
Molecular Weight ◽  
Whey Protein ◽  
Spray Drying ◽  
Protein Isolate ◽  
Droplet Breakup ◽  
Low Molecular Weight ◽  
Oil Droplets ◽  
Oil Droplet ◽  
Emulsifier System ◽  
Coalescence Times

Spray drying of whey protein-based emulsions is a common task in food engineering. Lipophilic, low molecular weight emulsifiers including lecithin, citrem, and mono- and diglycerides, are commonly added to the formulations, as they are expected to improve the processing and shelf life stability of the products. During the atomization step of spray drying, the emulsions are subjected to high stresses, which can lead to breakup and subsequent coalescence of the oil droplets. The extent of these phenomena is expected to be greatly influenced by the emulsifiers in the system. The focus of this study was therefore set on the changes in the oil droplet size of whey protein-based emulsions during atomization, as affected by the addition of low molecular weight emulsifiers. Atomization experiments were performed with emulsions stabilized either with whey protein isolate (WPI), or with combinations of WPI and lecithin, WPI and citrem, and WPI and mono- and diglycerides. The addition of lecithin promoted oil droplet breakup during atomization and improved droplet stabilization against coalescence. The addition of citrem and of mono- and diglycerides did not affect oil droplet breakup, but greatly promoted coalescence of the oil droplets. In order to elucidate the underlying mechanisms, measurements of interfacial tensions and coalescence times in single droplets experiments were performed and correlated to the atomization experiments. The results on oil droplet breakup were in good accordance with the observed differences in the interfacial tension measurements. The results on oil droplet coalescence correlated only to a limited extent with the results of coalescence times of single droplet experiments.

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 Oil-Water-Gas Three-Phase Separation in Multitube T-Junction Separators

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2655
Author(s):  
Lele Yang ◽  
Jing Wang ◽  
Yong Ma ◽  
Sen Liu ◽  
Jun Tang ◽  
...  
Keyword(s):  
Droplet Size ◽  
Oil Content ◽  
Gas Content ◽  
Separation Performance ◽  
Oil Separation ◽  
Oil Droplet ◽  
Inner Diameter ◽  
Oil Water ◽  
Water Gas ◽  
Oil Droplet Size

Multitube T-junctions can be used as an oil-water-gas pre-separator in the oil and gas industry. In this paper, the mixture model, coupled with the k-ε turbulent model, was applied for a simulation of the oil-water-gas three-phase flow characteristics in the multitube T-junction separator. The oil droplet size ranged from 1 to 4 mm. The water content ranged from 5% to 20% and the gas content from 3% to 25%. According to the phase separation results for different droplet sizes, it was found that, as the oil droplet size increased, the water content at the water outlet initially increased and then tended to be stable. Therefore, it was necessary to increase the oil droplet size through corresponding measures before flowing into the T-junction for separation. For the separator with an inner diameter of 50 mm, the oil content at the inlet had a great influence on the water-oil separation performance, and the water-oil separation performance was obviously improved as the oil content decreased. Owing to increased residence time, the oil content had little influence on the water-oil separation performance when the separator with an inner diameter of 100 mm was applied. Moreover, for the separator with an inner diameter of 100 mm, the oil content had little influence on the degassing effect, and more than 90% of the gas could be discharged from the gas outlet. The separation performance of the multitube T-junction separator became worse as the inlet gas content increased.

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