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Journal articles on the topic 'Atomizer'
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1
Wolfe, Timothy R., Todd A. Hillman, Philip J. Bossart, and David W. Kennedy. "The Comparative Risks of Bacterial Contamination between a Venturi Atomizer and a Positive Displacement Atomizer." American Journal of Rhinology 16, no. 4 (July 2002): 181–86. http://dx.doi.org/10.1177/194589240201600401.
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Introduction This laboratory study determined the incidence of internal contamination of Venturi principle atomizers and positive displacement atomizers exposed to high external concentrations of Staphylococcal aureus (Staph). Methods Atomizer device nozzle tips were immersed into a Staph solution and 1 ml of spray was atomized via compressed wall air (Venturi) or hydraulic pump (positive displacement). The Venturi nozzle was then wiped with 70% isopropyl alcohol while the disposable positive displacement nozzle was replaced. After 30 minutes, 1 ml of atomized fluid was collected and cultured and the process was repeated. After sixteen uses the fluid remaining in the bottles was cultured. The Venturi atomizer also was subjected to a single use trial to determine the location of device contamination. Results Venturi atomizers sprays grew Staph in every case (144/144), while positive displacement atomizer sprays never grew contaminants (0/144; p < 0.0001). At the end of 16 uses, 7/9 of Venturi atomizers had Staph within their medication reservoirs while none (0/9; p = 0.002) existed in the positive displacement atomizers. After a single use of the Venturi atomizer, the medication reservoir, the air lumen and the medication lumen of the nozzle were all contaminated with Staph. Conclusions External bacterial contamination of the atomizer nozzle tip results in internal bacterial contamination of Venturi devices in as little as one use but not of positive displacement devices. These results warrant further investigation to determine whether a risk of cross-contamination exists in a clinical setting.
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Achelis, Lydia, Volker Uhlenwinkel, S. Lagutkin, and Sh Sheikhaliev. "Atomization Using a Pressure-Gas-Atomizer." Materials Science Forum 534-536 (January 2007): 13–16. http://dx.doi.org/10.4028/www.scientific.net/msf.534-536.13.
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An update and the latest results on molten metal atomization using a Pressure-Gas- Atomizer will be given. This atomizer combines a swirl-pressure atomizer, to generate a liquid hollow cone film and a gas atomizer to atomize the film and/or the fragments of the film. The paper is focused on powder production, but this atomization system is also applicable for deposition purposes. Different alloys (Sn, SnCu) were atomized to study the characteristics of the Pressure- Gas-Atomizer. The powders produced were analyzed by laser diffraction and image processing. Among other parameters, the molten metal mass flow (~140 – 200 kg/h), the gas mass flow and the atomizer design were varied. The results include the effects of these variances on particle size and particle shape.
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Mlkvik, Marek, Matous Zaremba, Philipp Stähle, Heike P. Schuchmann, Volker Gaukel, and Jan Jedelsky. "Influence of Working Parameters and Primary Breakup Conditions on the Quality of Twin-Fluid Atomizers Spray Quality." Applied Mechanics and Materials 821 (January 2016): 91–96. http://dx.doi.org/10.4028/www.scientific.net/amm.821.91.
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In this study we investigated four twin-fluid atomizers with different internal mixing mechanisms: Y-jet, outside in gas (OIG), outside in liquid (OIL) and CFT atomizers. The main goal was to relate the measured droplet sizes, characterized by the Sauter mean diameter (ID32), to the corresponding working regimes of atomizers and primary breakup conditions characterized by the criterion Dmax, estimated from critical Weber number of the primary breakup. For the OIL, OIG and CFT atomizers, the common relation of the primary breakup characteristics and normalized droplet sizes (ID32/Dmax) was found. As the Y-jet atomizer showed a different trend, which was related to the considerably lower Weber numbers of the near-nozzle flow, a change in the normalization criterion was necessary to obtain similar results as for other tested atomizers. The main benefit of presented results is the potential to predict spray droplet sizes entirely from primary breakup characteristics regardless of the atomizer’s design or the atomized liquid.
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Chen, Yan, Chunyan Ma, Zaihe Shen, and Rui Chen. "Research on Vibration Characteristics of Piezoelectric Ceramic Atomizer Based on ANSYS." E3S Web of Conferences 118 (2019): 02043. http://dx.doi.org/10.1051/e3sconf/201911802043.
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In the design and application of ultrasonic atomizer, the resonant frequency and vibration mode of piezoelectric transducer have an effect on the working state and atomization effect of the atomizer. In order to deeply study the piezoelectric ceramic ultrasonic atomizer Vibration characteristics, piezoelectric coupling simulation analysis was performed by ANSYS software, multi-order vibration mode of piezoelectric ceramic atomization sheet obtained by modal analysis method, combined with harmonic response analysis to obtain resonant frequency of piezoelectric ceramic ultrasonic atomization sheet, and analysis the influence of the main size of the atomized sheet on the vibration mode. According to theoretical analysis and experimental tests, the effectiveness of the finite element analysis can be verified, and then provide a theoretical basis for the study of ultrasonic atomizers.
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Czernek, Krystian, Marek Ochowiak, and Sylwia Włodarczak. "Effect of Rheological Properties of Aqueous Solution of Na-CMC on Spray Angle for Conical Pressure-Swirl Atomizers." Energies 13, no. 23 (November 30, 2020): 6309. http://dx.doi.org/10.3390/en13236309.
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Aerosol is a multiphase system, created as a result of the dispersion of a liquid in a gaseous medium. The atomized liquids are most often water and fuel; however, they can be any other substance. Even a small addition of a substance that changes the rheological properties (i.e., the nature of the flow) can change the properties of the resulting aerosol. The most important parameters that characterize the aerosol are the outflow rate, the droplet diameter, the spray spectrum, and the spray angle. The latter is important when selecting atomizers, especially those working in groups on the sprayer boom. The spray angle is an important parameter of the atomization process, providing a great deal of information about the quality of the spray. This study presents the results of rheological tests and the atomization of aqueous solutions with varying concentrations of sodium carboxymethylcellulose (Na-CMC). We found that the spray angle decreased with increasing Na-CMC concentration in the solution, which is attributable to an increase in shear viscosity. The design of the atomizer is also important. The largest spray angles were obtained for an atomizer with a diameter of 0.02 m and with the inlet port being placed at an angle to the atomizer axis. Based on the experimental results for various liquids and atomizer designs, a correlation equation describing the spray angle is proposed.
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Scianna, Joseph M., James M. Chow, and Andrew Hotaling. "Analysis of Possible Cross-Contamination with the Venturi System Atomizer." American Journal of Rhinology 19, no. 5 (September 2005): 503–7. http://dx.doi.org/10.1177/194589240501900514.
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Background The physics behind the Venturi atomizers suggest a possibility of bacterial colonization and the potential for patient cross-contamination. A protocol for use of the atomizer and clinically appropriate demonstration of cross contamination has not been established. Methods Three sterilized atomizers filled with a solution of 2% Pontocaine and 1% ephedrine (two test and one control) were used during a 5-day study period. Clinic staff was instructed to (1) use a nozzle tip, (2) use a nasal speculum, (3) avoid contact between the atomizer and the patient, and (4) apply a continuous, <1-second spray to the nasal cavity. Samples were obtained from each of the atomizers three times per day and plated on chocolate agar plates. The number and type of bacterial colony were registered. Results No respiratory pathogens grew from any of the 45 plated samples. Nine of 30 experimental atomizer samples produced 12 bacterial colonies. Of the 12 bacterial colonies obtained, 6 colonies of coagulase-negative Staphylococcus, 5 colonies of Corynebacterium sp., and 1 colony of Bacillus sp. were identified. One of 15 plated control atomizer samples produced two colonies of coagulase-negative Staphylococcus. An average of 1.3 colonies per positive test plate and an average of 2.0 colonies per positive control plate were identified. There was no evidence of an increasing number of colonies per plate or persistence of any particular bacteria identified over time to suggest contamination or colonization of the system reservoir. Conclusion There is no risk of cross-contamination of patients with the use of the Venturi system atomizer as outlined in this study. Culture results from this study were consistent with random culture contamination during the plating and/or culturing period. There was no evidence to support the idea of bacterial colonization of the atomizers. Continued use of the Venturi system atomizer is an acceptable practice.
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Cejpek, Ondřej, Milan Malý, Miloslav Bělka, and Jan Jedelský. "Replication of Pressure Swirl Atomizer by 3D Printing and Influence of Surface Roughness on the Atomization Quality." MATEC Web of Conferences 328 (2020): 01007. http://dx.doi.org/10.1051/matecconf/202032801007.
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The replication of atomizers by 3D printing technology is a new approach of producing the pressure swirl atomizers. The surface roughness of 3D printed products and manufacturing accuracy of the 3D printing process influence the atomization of the liquid. The high-speed visualization of a spray, produced by scaled 3D printed atomizer, was performed. The spray stability, cone angle and breakup length were determined. Scaled 3D printed atomizers were tested at equivalent pressures of 0.25, 0.5 and 1 bar. Non-dimensionless parameter, Reynolds number, was preserved for the scaled atomizer. The effect of the surface roughness of the tangential ports, swirl chamber and discharge orifice on atomization was assessed at non-scaled pressure swirl atomizer. The roughness of a swirl chamber was created by corundum and ballotin blasting. The inlet pressures of 2.5, 5 and 10 bar were tested.
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Jo, Jae Geun, and Chi Young Lee. "Experimental Study on Thermal Radiation Attenuation Using Water Mist of Twin-fluid Atomizer." Fire Science and Engineering 35, no. 4 (August 31, 2021): 24–32. http://dx.doi.org/10.7731/kifse.67a3ae31.
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In this study, the thermal radiation attenuation performance of water mist was investigated using twin-fluid atomizers. The water and air flow rates of Small atomizer were 36~105 g/min and 10~30 L/min, whereas those of Large atomizer were 37~300 g/min and 20~60 L/min, respectively. In the present experimental range, the thermal radiation attenuation of Small atomizer and Large atomizer were 6.1~11.9% and 5.2~14.6%, respectively. With the increase in water and air flow rates, the thermal radiation attenuation increased, and under similar water and air flow rate conditions, Small atomizer showed higher thermal radiation attenuation than Large atomizer. Based on the present experimental data, it was found that the air (gas) discharge area is a potentially important factor in determining the thermal radiation attenuation performance. Additionally, through the analysis of thermal radiation attenuation per unit water flow rate, it was confirmed that the twin-fluid atomizer can result in higher thermal radiation attenuation than the single-fluid atomizer under the same water flow rate condition.
9
Ding, You Qing. "The Comparison Study on the Performance of Centrifugal Atomizer." Advanced Materials Research 726-731 (August 2013): 1968–71. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.1968.
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High speed rotating centrifugal atomizer is the key equipment for the flue gas processing. The centrifugal high-speed atomizer is running at high speed, it makes micron liquid-drop in order that chemical reaction happened between micron drop and harmful gas. Its function has direct impact to the emission produced from WTE(waste to energy) plant. The different driving form affects the atomizers stability of high speed movement, atomization effect and the running life directly. For a long time, the transmission quality of belt drive or direct coupling drive is one of the focus issues. Based on the high speed centrifugal atomizer, this paper introduces the two commonly used driving forms of the atomizer, and compares their performance through the experiments. Key words: atomizer, WTE, experiment
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Williams, Monique, and Prue Talbot. "Design Features in Multiple Generations of Electronic Cigarette Atomizers." International Journal of Environmental Research and Public Health 16, no. 16 (August 14, 2019): 2904. http://dx.doi.org/10.3390/ijerph16162904.
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The design of electronic cigarette (EC) atomizing units has evolved since their introduction over 10 years ago. The purpose of this study was to evaluate atomizer design in ECs sold between 2011–2017. Atomizers from 34 brands representing three generations of ECs were dissected and photographed using a stereoscopic microscope. Five distinct atomizer design categories were identified in first generation products (cig-a-like/cartomizer) and three categories were found in the third generation. Atomizers in most cig-a-like ECs contained a filament, thick wire, wire joints, air-tube, wick, sheath, and fibers, while some later models lacked some of these components. Over time design changes included an increase in atomizer size; removal of solder joints between wires; removal of Polyfil fibers; and removal of the microprocessor from Vuse. In second and third generation ECs, the reservoirs and batteries were larger, and the atomizing units generally lacked a thick wire, fibers, and sheath. These data contribute to an understanding of atomizer design and show that there is no single design for ECs, which are continually evolving. The design of the atomizer is particularly important as it affects the performance of ECs and what transfers into the aerosol.
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Colding-Jorgensen, J. "Fluid-Induced Rotordynamic Instability in Rotary Atomizers." Journal of Engineering for Gas Turbines and Power 111, no. 2 (April 1, 1989): 318–24. http://dx.doi.org/10.1115/1.3240254.
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A theory is presented for the calculation of rotordynamic coefficients for the fluid-rotor interaction in rotary atomizers, based on calculation of the fluid flow through a whirling atomizer wheel. The theory predicts potentially unstable rotor whirl in high-speed rotary atomizers. The whirl frequency can be that of the first critical forward or the first critical backward precession of the rotor, depending on atomizer wheel geometry, speed, fluid properties, and flow rate. The predicted whirl phenomena have been produced in an atomizer test stand. Both forward and backward precession have been observed to become unstable. The observed whirl directions and amplitudes are consistent with the calculated coefficients. Some design parameters are identified that can help control and suppress the whirl.
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Gebhardt, Maurice R. "Rotary Disk Atomization." Weed Technology 2, no. 1 (January 1988): 106–13. http://dx.doi.org/10.1017/s0890037x00030189.
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In the late 1930s, European engineers discovered that, for very low flow rates, rotary disk atomizers produced a more definable range of droplet sizes than hydraulic atomizers. In the late 1970s, a cup-like spinning atomizer was developed to apply herbicides at low and ultra-low volumes. Rotary atomizers distribute droplets in a pattern similar to hollow cone nozzles. The droplet trajectory could affect deposits adversely since droplets released horizontally are exposed to wind and other environmental effects longer than hydraulic spray nozzles. Propellers and fans were used to enhance downward movement of droplets without considering that droplet impingement velocity was critical for efficient deposition. In the early 1980s, rotary atomizers were promoted to reduce herbicide rates, but the claims were products of unconfirmed testing. Herbicide efficacy in confirmed research was not influenced by application with the rotary atomizer, but lower carrier rates reduced the amount of water handled during the spraying operation. The cost of the atomizer, more maintenance, and greater care during operation with no decrease in herbicide rates discourage continued use.
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Sidorenko, Ivan, Peter Dogoda, and Alexander Mashkov. "Hydrodynamics of formation of a microdispersed spray by the cup rotary atomizer." E3S Web of Conferences 176 (2020): 04009. http://dx.doi.org/10.1051/e3sconf/202017604009.
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This article is devoted to the study of the movement of a single drop inside an air-liquid jet formed by a cup atomizer. The relevance of the research topic is proved. The problem, which has been identified, is about using modern fan sprayers for chemical protection of agricultural crops, in particular, orchards and vineyards. As for mechanical spraying, the process of movement of the droplet inside the torch, the trajectory of droplet flight, as well as the dependence of these indicators on the parameters of the rotary atomizers are currently very little studied. Therefore, this article considers the laws describing the movement of one droplet on the surface of the rotating working element and one droplet flight in atmospheric air after escape from the surface of the rotary atomizer’s cup. Research results are presented as the equations describing the dependence of the torch boundaries on the parameters of the rotary cup atomizer.
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Denmud, Nipon, and Thawatchai Plookphol. "Characteristics of SAC305 Lead-Free Powder Prepared by Centrifugal Atomization." Key Engineering Materials 777 (August 2018): 322–26. http://dx.doi.org/10.4028/www.scientific.net/kem.777.322.
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Centrifugal atomization apparatus was constructed to produce solder alloy powder with high quality. In this work, SAC305 alloy was atomized to study the effects of processing parameters, including atomizer disk surface condition and oxygen content in the atomizer chamber on the mean particle size, size distribution, production yield, and morphology of the produced SAC305 powder. The results showed that the atomizer disk surface coated with tin alloy gave the produced powder with smaller mean size, narrower size distribution and higher production yield, in comparison with the uncoated disk. This is due to a good wettability between the molten SAC305 and atomizer disk surface and the sufficient time for alloy droplets to be solidified. The shapes of SAC305 powder were sphere, teardrop, oval, and ligament, depending on the oxygen content in the atomizer chamber during atomization. The shape of produced powder was almost perfectly spherical when the oxygen content was decreased down to 0.5 vol.%. Moreover, with decreasing the oxygen content in the atomizer chamber, the produced SAC305 powder would contain oxygen content on its surface lower than 100 ppm.
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Kudryashova, Olga, Evgeny Muravlev, Boris Vorozhtsov, and Igor Akhmadeev. "The role of cavitation in submicron aerosol dispersion." MATEC Web of Conferences 243 (2018): 00003. http://dx.doi.org/10.1051/matecconf/201824300003.
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Here we discuss the problem of atomizing submicron aerosols by special design atomizers enabling the cavitation regime. The formation of submicron aerosol was studied using an impulse atomizer model powered by a high-energy material and an atomizer model with a special spray nozzle generating countercurrent flows. For these atomizers, the role played by cavitation in producing submicron liquid aerosols is demonstrated herein. A mathematical model is also suggested to describe the aerosol cloud genesis. The cavitation development critical pressure, outflow velocity, and the resulting droplet sizes were evaluated. The aerosol particle size and concentration were experimentally measured by optical methods. The measured disperse parameters of aerosols during the origination and propagation of the aerosol cloud resulted from the cavitation-assisted atomization of liquids are reported: the intrinsic particle diameter of water aerosol is 10…30 μm depending on the features of the atomizer designs and their operating regimes.
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Zhu, Xin Cai, Teng Fei Hu, Lei Guo, Xiong Zhou, You Qing Ding, and Xing Deng. "The Study on the Performance of Two Drive Forms of Centrifugal Atomizer." Applied Mechanics and Materials 233 (November 2012): 324–27. http://dx.doi.org/10.4028/www.scientific.net/amm.233.324.
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High speed rotating centrifugal atomizer is the key part in the flue gas processing. The different driving form affects the atomizer's stability of high speed movement, atomization effect and the running life directly. For a long time, the transmission quality of belt drive or direct coupling drive is one of the focus issues. Based on the high speed centrifugal atomizer, this paper introduces the two commonly used driving forms of the atomizer, and compares their performance through the experiments.
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Yan, Qiufeng, Chuanyu Wu, and Jianhui Zhang. "Effect of the Dynamic Cone Angle on the Atomization Performance of a Piezoceramic Vibrating Mesh Atomizer." Applied Sciences 9, no. 9 (May 3, 2019): 1836. http://dx.doi.org/10.3390/app9091836.
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In this paper, we find that the dynamic cone angle of a piezoceramic atomizer is linked to periodic changes in the volume of the micro-cone hole of the atomizer, and such changes affect atomization performance. Firstly, we explained the theory of the dynamic cone angle inside the vibrating mesh atomizer. Then, we analyzed the flow status of liquid in the micro-cone hole, and the one-way flow Rof the liquid is caused by the difference of diffuser and nozzle flow resistance. The volume change of the micro-cone hole and the liquid chamber can produce atomization. Furthermore, we developed the experiment to measure the atomization rate, atomization height, and the diameter of the atomized particles. The experiments reveal that the atomization rate and height are much larger when the vibrating mesh atomizer is working in the forward path than in the reverse one. The atomization rate and atomization height increase as the working voltage increases. Meanwhile, with increasing driving voltage to the piezoceramic actuator, the atomization particle size decrease and the atomized particle size distribution is more concentrated. Finally, the size of the micro-cone hole was measured using a microscope with different direct current (DC) voltages, further demonstrating the existence of the dynamic cone angle.
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Baltrėnas, Pranas, and Edita Baltrėnaitė-Gedienė. "Research of Modified Atomizers and Their Application for Moistening of Air-Cleaning Device Charges." Sustainability 11, no. 19 (October 6, 2019): 5522. http://dx.doi.org/10.3390/su11195522.
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The size of sprayed droplets is a very important parameter that influences the operational efficiency of air-cleaning device charges. It is desirable for atomizers to spray droplets that are dispersed as much as technically and economically reasonable and possible. Fine dispersion spraying ensures effective moistening of the air-cleaning device charges, as well as an optimal consumption of water or other liquids. Three modifications of special atomizers were used for experimental analysis. The atomization of liquid and spraying in the special atomizer occurs when two frontal streams confront each other. Frontal streams are formed by an inner shield located in the special atomizer. The experiment was conducted using different spraying pressures, namely: 6 bar, 4 bar, 2 bar. The evaluation (performed using a microscope) of the size of sprayed droplets shows that the best (finest) spraying was by the special atomizer of modification 3. The depth of the channel of the inner shield is the parameter that has the biggest influence on the size of sprayed droplets. The special atomizer of modification 3 produces droplets with the following size distribution and rates: ≤0.05 mm—63.2 vol%; 0.2–0.6 mm—28.3 vol%; 0.6–1.0 mm—8.1 vol%; ≥1.0 mm—0.4 vol%.
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Omaiye, Esther E., Monique Williams, Krassimir N. Bozhilov, and Prue Talbot. "Design features and elemental/metal analysis of the atomizers in pod-style electronic cigarettes." PLOS ONE 16, no. 3 (March 9, 2021): e0248127. http://dx.doi.org/10.1371/journal.pone.0248127.
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Background The atomizers of electronic cigarettes (ECs) contain metals that transfer to the aerosol upon heating and may present health hazards. This study analyzed 4th-generation EC pod atomizer design features and characterized their elemental/metal composition. Methods Eleven EC pods from six brands/manufacturers were purchased at local shops and online. Pods were dissected and imaged using a Canon EOS Rebel SL2 camera. Elemental analysis and mapping of atomizer components was done using a scanning electron microscope coupled with an energy dispersive x-ray spectrometer. Results EC pods varied in size and design. The internal atomizer components were similar across brands except for variations occurring mainly in the wicks and filaments of some products. The filaments were either Elinvar (nickel, iron, and chromium) (36.4%), nichrome (36.4%), iron-chromium (18.2%), or nickel (9%). Thick wires present in 55% of the atomizers were mainly nickel and were joined to filaments by brazing. Wire-connector joints were Elinvar. Metal air tubes were made of Elinvar (50%), nickel, zinc, copper, and tin (37.5%), and nickel and copper (12.5%). Most of the wick components were silica, except for two pods (PHIX and Mico), which were mainly ceramic. Connectors contained gold-plated nickel, iron-chromium multiple alloys of nickel, zinc, gold, iron, and copper. Wick chambers were made of Elinvar. Outer casings were either nickel, copper-tin, or nickel-copper alloys. Magnets were nickel with minor iron, copper, and sulfur. Some frequently occurring elements were high in relative abundance in atomizer components. Conclusions The atomizers of pods are similar to previous generations, with the introduction of ceramic wicks and magnets in the newer generations. The elements in EC atomizers may transfer into aerosols and adversely affect health and accumulate in the environment.
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Levitsky, Inna, and Dorith Tavor. "Improved Atomization via a Mechanical Atomizer with Optimal Geometric Parameters and an Air-Assisted Component." Micromachines 11, no. 6 (June 11, 2020): 584. http://dx.doi.org/10.3390/mi11060584.
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Atomization of liquid media is a key aim in various technological disciplines, and solutions that improve spray performance, while decreasing energy consumption, are in great demand. That concept is very important in the development of liquid fuel spray atomizers in high-efficiency microturbines and other generator systems with low inlet pressure and a wide range of power supply. Here we present a study of the liquid atomization characteristics for a new mechanical atomizer that has optimal geometric parameters and a preliminary swirl stage. In our air-assisted atomizer, air is introduced through a swirl chamber positioned at the exit of the mechanical atomizer. The optimized mechanical atomizer alone can achieve D32 drop diameters in the range of 80 to 40 µm at water supply pressures of 2 to 5 bar, respectively. The addition of an air swirl chamber substantially decreases drop sizes. At an air–liquid ratio (ALR) equal to 1, water pressures of 2.5 to 3 bar and air supply pressures 0.35 to 1 bar, D32 drops with diameters of 20–30 µm were obtained. In an air-assisted atomizer the parameters of the mechanical atomizer have a much stronger influence on drop diameters than do characteristics of the air-swirl chamber. Using a mechanical atomizer with optimal geometrical dimensions allows limiting the liquid supply pressure to 5 bar; but when an air-assisted component is introduced we can recommend an ALR ≈ 1 and an air supply pressure of up to 1 bar.
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Pavlovic, Mirjana, Jelena Savovic, and Momir Marinkovic. "Some problems connected with boron determination by atomic absorption spectroscopy and the sensitivity improvement." Journal of the Serbian Chemical Society 66, no. 8 (2001): 535–42. http://dx.doi.org/10.2298/jsc0108535p.
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Two atomizers were compared: an N2O-C2H2 flame and a stabilized U-shaped DC arc with aerosol supply. Both the high plasma temperature and the reducing atmosphere obtained by acetylene addition to the argon stream substantially increase the sensitivity of boron determination by atomic absorption spectroscopy (AAS) when the arc atomizer is used. The results were compared with those for silicon as a control element. The experimental characteristic concentrations for both elements were compared with the computed values. The experimentally obtained characteristic concentration for boron when using the arc atomizer was in better agreement with the calculated value. It was estimated that the influence of stable monoxide formation on the sensitivity for both elements was about the same, but reduction of analyte and formation of non-volatile carbide particles was more important for boron, which is the main reason for the low sensitivity of boron determination using a flame atomizer. The use of an arc atomizer suppresses this interference and significantly improves the sensitivity of the determination.
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Mlkvik, Marek, Jan Jedelsky, Heike P. Karbstein, and Volker Gaukel. "Spraying of Viscous Liquids: Influence of Fluid-Mixing Mechanism on the Performance of Internal-Mixing Twin-Fluid Atomizers." Applied Sciences 10, no. 15 (July 30, 2020): 5249. http://dx.doi.org/10.3390/app10155249.
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The thermal usage of liquid fuels implies their combustion, which is a process strongly influenced by the performance of the atomizer, which disrupts the fuel into drops of the required sizes. The spray quality of the twin-fluid atomizers with internal mixing (IM-TFA) is primarily influenced by the two-phase flow pattern inside the mixing chamber. We studied the performance of the four types of the IM-TFA nozzles by the optical diffraction system (Malvern Spraytec) to answer the question of how the mixing chamber design influences the spray quality at low atomizing gas consumption. We tested the effervescent atomizer in outside-in-liquid (OIL) and outside-in-gas (OIG) configurations, the Y-jet nozzle and new nozzle design, and the CFT atomizer when spraying model liquids with the viscosities comparable to the common fuels (μ=60and143 mPa· s). We found that the effervescent atomizer performance was strongly influenced by the configuration of the inlet ports. Although the OIL configuration provided the best spray quality (D32 = 72 μm), with the highest efficiency (0.16%), the OIG nozzle was characterized by unstable work and poor spray quality. Both the devices were sensitive to liquid viscosity. The Y-jet nozzle provided a stable performance over the liquid viscosity spectrum, but the spray quality and efficiency were lower than for the OIL nozzle. Our findings can be used to improve the performance of the common IM-TFA types or to design new atomizers. The results also provide an overview of the tested atomizers’ performances over the wide range of working conditions and, thus, help to define the application potential of the tested nozzle designs.
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Wang, Muh Ron, Pin Jen Chen, Je Rei Yang, Jin Shen Chiu, Tien Chu Lin, and Teng Sun Lai. "Combination of Spray Forming and Metal Powder Productions by the Internal Mixing Atomizer with a Substrate." Materials Science Forum 505-507 (January 2006): 1237–42. http://dx.doi.org/10.4028/www.scientific.net/msf.505-507.1237.
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This paper describes the performance of an atomizer coupled with a substrate which produces metal powder and spray forming materials simultaneous in the spray chamber. Ultra fine metal powders are produced from this process. The melt is atomized by a twin-fluid atomizer with internal mixing mechanisms. The molten spray injected from the swirling chamber of the atomizer is then impinged upon the substrate to form the two phase impinging flow. The deposition rate of the molten spray on the substrate is controlled by the diameter of the substrate, the height of the substrate ring and the distance of the substrate from the outlet of the atomizer. This in turn determines the powder production rate of the spraying processes. Experimental results indicate that the deposition rate of the spray forming material decreases as the distance between the substrate and the atomizer increases. For example, the deposition rate decreases from 48% to 19% as the substrate is placed at a distance from 20cm to 40cm. On the other hand, the metal powder production rate and its particle size increases as the substrate is placed far away from the atomizer. The production of metal powder with mean particle size as low as 3μ m level has been achieved, a level which is not achievable by the conventional gas atomization processes.
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Souza, E. J. J., and M. J. J. S. Ponte. "EXPERIMENTAL METHOD FOR SPRAY VELOCITY FIELD PREDICTION MODEL IN PRESSURE SWILL ATOMIZERS." Revista de Engenharia Térmica 9, no. 1-2 (December 31, 2010): 55. http://dx.doi.org/10.5380/reterm.v9i1-2.61931.
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Pressure swill atomizers are widely used in engineering as an effective device for vaporization and liquid mass transfer in physical or chemical processes. Among many applications those atomizers are used in modern fuel injection systems for spark engines. An even fuel and air mixture may increase the overall engine performance by higher efficiency and low flue gas emissions. In applied atomization, one of the most important characteristics is the spray velocity field prediction. Droplet sizing models are also important, but they are relatively popular on books and papers. By the other hand spray velocity field prediction and profile is relatively rare. This work focus on the prediction of the velocity field of pressure swirl atomize by means of an experimental approach and applied statistics. For the spray measurements this study used a non-intrusive, quantitative method by Laser Doppler Interpherometry (LDI) for the spray velocity field and droplet sizing. Also four models for the film thickness calculation at atomizer discharge are compared considering their statistical significance.
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Rizk, N. K., J. S. Chin, and M. K. Razdan. "Modeling of Gas Turbine Fuel Nozzle Spray." Journal of Engineering for Gas Turbines and Power 119, no. 1 (January 1, 1997): 34–44. http://dx.doi.org/10.1115/1.2815559.
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Satisfactory performance of the gas turbine combustor relies on the careful design of various components, particularly the fuel injector. It is, therefore, essential to establish a fundamental basis for fuel injection modeling that involves various atomization processes. A two-dimensional fuel injection model has been formulated to simulate the airflow within and downstream of the atomizer and address the formation and breakup of the liquid sheet formed at the atomizer exit. The sheet breakup under the effects of airblast, fuel pressure, or the combined atomization mode of the airassist type is considered in the calculation. The model accounts for secondary breakup of drops and the stochastic Lagrangian treatment of spray. The calculation of spray evaporation addresses both droplet heat-up and steady-state mechanisms, and fuel vapor concentration is based on the partial pressure concept. An enhanced evaporation model has been developed that accounts for multicomponent, finite mass diffusivity and conductivity effects, and addresses near-critical evaporation. The presents investigation involved predictions of flow and spray characteristics of two distinctively different fuel atomizers under both nonreacting and reacting conditions. The predictions of the continuous phase velocity components and the spray mean drop sizes agree well with the detailed measurements obtained for the two atomizers, which indicates the model accounts for key aspects of atomization. The model also provides insight into ligament formation and breakup at the atomizer exit and the initial drop sizes formed in the atomizer near field region where measurements are difficult to obtain. The calculations of the reacting spray show the fuel-rich region occupied most of the spray volume with two-peak radial gas temperature profiles. The results also provided local concentrations of unburned hydrocarbon (UHC) and carbon monoxide (CO) in atomizer flowfield, information that could support the effort to reduce emission levels of gas turbine combustors.
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Ochowiak, Marek, Andżelika Krupińska, Sylwia Włodarczak, Magdalena Matuszak, Małgorzata Markowska, Marcin Janczarek, and Tomasz Szulc. "The Two-Phase Conical Swirl Atomizers: Spray Characteristics." Energies 13, no. 13 (July 2, 2020): 3416. http://dx.doi.org/10.3390/en13133416.
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This paper presents the results of experimental studies on two-phase conical swirl atomizers. The impact of various atomizer geometries and different operational parameters of the atomization process on the spray characteristics was investigated. The influence of the mixing chamber height HS to diameter DS ratio and the volumetric flow rates of liquid and gas on the discharge coefficient values, spray angle, droplet size expressed by Sauter mean diameter D32, volumetric and radial distributions of droplet diameters in the spray stream were determined. The analysis of results showed that the discharge coefficient values depend on the Reynolds number for liquid and gas and the atomizer geometry. The spray angle increases as the flow rate of liquid and gas increases depending on the applied atomizer construction. The Sauter mean diameter value is correlated with the geometric dimensions of the atomizer swirl chamber. The rapid increase in D32 occurs after exceeding the value HS/DS ≈ 3. The Sauter mean diameter also depends on the operating parameters. A central area of stream is filled with smaller sized droplets as the gas flow rate increases.
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Yao, Jiafeng, Shinji Furusawa, Akimaro Kawahara, and Michio Sadatomi. "INFLUENCE OF SOME GEOMETRICAL PARAMETERS ON THE CHARACTERISTICS OF PREFILMING TWIN-FLUID ATOMIZATION." Transactions of the Canadian Society for Mechanical Engineering 38, no. 3 (September 2014): 391–404. http://dx.doi.org/10.1139/tcsme-2014-0028.
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Geometries are considered to have a great influence on the spray characteristics of atomizers. In the present study, we studied a prefilming twin-fluid atomizer patented by Sadatomi and Kawahara (2012), in which liquid atomization is implemented by supplying compressed air alone into an internal mixing chamber, and water is automatically sucked by the negative pressure induced by an orifice. In the experiments, we studied spray characteristics influenced by the geometrical parameters, such as orifices in different opening area ratios and different shapes, porous rings with different porous diameters, and different atomizer sizes. Higher spray performance can be obtained by a small sized atomizer with a circular orifice in opening area ratio of 0.429 and a porous fiber ring with porosity of 25 μm. The present results provide a significant guidance for practical applications with different requirements of spray characteristics.
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Ochowiak, Marek, Daniel Janecki, Andżelika Krupińska, Sylwia Włodarczak, Tomasz Wilk, and Radosław Olszewski. "Conical Two-Phase Swirl Flow Atomizers—Numerical and Experimental Study." Energies 14, no. 6 (March 21, 2021): 1745. http://dx.doi.org/10.3390/en14061745.
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This paper presents the results of numerical simulations for the developed and discussed conical two-phase atomizers with swirl flow, differing in the ratio of the height of the swirl chamber to its diameter. Experiments were carried out for SAN-1 with HS/DS = 1 and SAN-2 with HS/DS = 4 atomizers. The study was conducted over a range of Reynolds number for liquid ReL = (1400; 5650) and for gas ReG = (2970; 9900). Numerical calculations were performed with the use of computational fluid dynamics (CFD), which were verified on the basis of experimental data. Based on the analysis of experimental studies and simulations results the influence of operational parameters and changes of the atomizer geometry on the generated spray was demonstrated. As the gas flow rate increased and the swirl chamber height decreased, the spray angle increased. Higher velocity values of the liquid and greater turbulence occur in the center of the spray. The flow inside the atomizer determines the nature of the spray obtained. The geometry of the swirl chamber influences the air core formed inside the atomizer, and this determines the atomization effect. The results of numerical simulations not only confirm the results of experimental studies, but also provide additional information on internal and external fluid flow.
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Flanagan, Cormac, and Stephen N. Freund. "Atomizer." ACM SIGPLAN Notices 39, no. 1 (January 2004): 256–67. http://dx.doi.org/10.1145/982962.964023.
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Boroday, S. "Cavitation in atomizer channels of water-mist Fi-Fi systems." Transactions of the Krylov State Research Centre 1, no. 395 (March 9, 2021): 109–18. http://dx.doi.org/10.24937/2542-2324-2021-1-395-109-118.
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Object and purpose of research. This paper discusses insufficient flow rate in a standard swirl atomizer of ma-rine water-mist Fi-Fi systems. The purpose of this study was to find the reasons for this insufficient flow rate and the ways to improve it. Materials and methods. This research was a computer-based simulation (in commercial ANSYS CFX package for engineering analysis) based on modern methods of computational fluid dynamics (CFD). Main results. An upgraded swirler for high-flow atomizer preventing cavitation in its inner channels. Conclusion. These results make it possible to design atomizers and sprinklers of marine water-mist Fi-Fi systems with cavitation-free swirler channels.
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Kim, Dong Hwan, Chi Young Lee, and Chang Bo Oh. "Effects of Discharge Area and Atomizing Gas Type in Full Cone Twin-Fluid Atomizer on Extinguishing Performance of Heptane Pool Fire under Two Heat Release Rate Conditions in an Enclosed Chamber." Applied Sciences 11, no. 7 (April 5, 2021): 3247. http://dx.doi.org/10.3390/app11073247.
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In this study, the effects of discharge area and atomizing gas type in a twin-fluid atomizer on heptane pool fire-extinguishing performance were investigated under the heat release rate conditions of 1.17 and 5.23 kW in an enclosed chamber. Large and small full cone twin-fluid atomizers were prepared. Nitrogen and air were used as atomizing gases. With respect to the droplet size of water mist, as the water and air flow rates decreased and increased, respectively, the Sauter mean diameter (SMD) of the water mist decreased. The SMD of large and small atomizers were in the range of approximately 12–60 and 12–49 μm, respectively. With respect to the discharge area effect, the small atomizer exhibited a shorter extinguishing time, lower peak surface temperature, and higher minimum oxygen concentration than the large atomizer. Furthermore, it was observed that the effect of the discharge area on fire-extinguishing performance is dominant under certain flow rate conditions. With respect to the atomizing gas type effect, nitrogen and air appeared to exhibit nearly similar extinguishing times, peak surface temperatures, and minimum oxygen concentrations under most flow rate conditions. Based on the present and previous studies, it was revealed that the effect of atomizing gas type on fire-extinguishing performance is dependent on the relative positions of the discharged flow and fire source.
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Ghaffar, Zulkifli Abdul, Salmiah Kasolang, and Ahmad Hussein Abdul Hamid. "Characteristics of Swirl Effervescent Atomizer Spray Angle." Applied Mechanics and Materials 607 (July 2014): 108–11. http://dx.doi.org/10.4028/www.scientific.net/amm.607.108.
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In the application of sprays produced by an atomizer, spray angle is one of key performance parameters. A larger spray angle is often required in providing a better spray dispersion. Swirl effervescent atomizer is one of the existing atomizers with the capability to produce a large spray angle. The formation of spray angle from this atomizer however is hardly understood. A newly-designed swirl effervescent atomizer was developed and tested with different swirl-generating vane angle in order to understand the swirl intensity effect on the spray angle. Experiments were carried out based on a cold flow test approach using water as the working fluid and nitrogen gas as the atomizing agent. High-speed shadowgraph technique was deployed to record the resultant sprays produced. Video recordings, acquired using a high-speed video camera, were converted to a sequence of images for further analysis using an image processing software. It was found that the spray angle increases with the swirl-generating vane angle. Specifically, the spray angle shows an abrupt increase for the case of swirl-generating vane angle changing from 30° to 45° but visualizes only a gradual increase in the case of swirl-generating vane angle changing from 45° to 60°.
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Rizk, N. K., and H. C. Mongia. "Calculation Approach Validation for Airblast Atomizers." Journal of Engineering for Gas Turbines and Power 114, no. 2 (April 1, 1992): 386–94. http://dx.doi.org/10.1115/1.2906603.
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In order to formulate a common approach that could provide the spray parameters of airblast atomizers, various processes of liquid preparation, breakup, and secondary atomization have been included in a semi-analytical calculation procedure. The air velocity components in the atomizer flow field are provided by mathematical expressions, and the spray droplets are considered to form at ligament breakup through a disturbance wave growth concept. The validation of the developed approach included the application to six atomizers that significantly varied in concept, design, and size. They represented both prefilming and plain-jet types, and the data utilized in the present effort were obtained with six different liquids. Satisfactory agreement between the measurements and the predictions has been achieved under wide ranges of air/fuel ratio and air pressure drop for various test liquids. The results of this investigation indicate the potential of using such an approach in the early phases of airblast atomizer design, and may be followed by more detailed calculations using analytical tools.
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Soulet, Sébastien, Marie Duquesne, Jean Toutain, Charly Pairaud, and Hélène Lalo. "Influence of Coil Power Ranges on the E-Liquid Consumption in Vaping Devices." International Journal of Environmental Research and Public Health 15, no. 9 (August 28, 2018): 1853. http://dx.doi.org/10.3390/ijerph15091853.
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As electronic cigarettes (e-cigarettes) represent a new constantly evolving product category, the systematic analysis of the developed devices and the e-liquid vaporization is challenging. Indeed, understanding how e-cigarettes work and the role of key parameters in the process are major issues. This work focuses on an experimental study of how the power supplied by the battery to the atomizer coil influences e-liquid consumption. The reproducibility and the repeatability of e-liquid consumption were investigated over 20 series of 20 puffs for one of the tested atomizers. Then, the reproducibility and the repeatability of the e-liquid consumption was investigated over five series of 20 puffs for each tested atomizer. The wire behavior according to the supplied power could be separated into three regimes: under-heating (insufficient power to generate an aerosol), optimal vaporization characterized by a linear trend (vaporization of the e-liquid proportional to the supplied energy) and over-heating (dry-burn occurs). Using a controllable and repeatable energy supply, the reproducibility of the quantity of vaporized e-liquid was verified for each of the five series of 20 puffs programed for all the atomizers except one. Finally, the influence of the supplied power on the vaporization and the consumption of the e-liquid as well as the optimal power ranges were investigated and discussed. The results showed that atomizers with resistance ranging from 1 Ω to 1.8 Ω are efficient using all the energy supplied by the battery to vaporize the e-liquid and reducing the energy lost in the cotton or in the metal part of atomizer coil.
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Song, Yu-Lin, Chih-Hsiao Cheng, Manoj Kumar Reddy, and Md Saikhul Islam. "Simulation of Onset of the Capillary Surface Wave in the Ultrasonic Atomizer." Micromachines 12, no. 10 (September 23, 2021): 1146. http://dx.doi.org/10.3390/mi12101146.
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The novel drug delivery system refers to the formulations and technologies for transporting a pharmaceutical compound in the body as it is needed to safely achieve its desired therapeutic effects. In this study, the onset vibrational amplitude of capillary surface waves for ultrasonic atomization spray is explained based on Faraday instability. Using ultrasonic frequency, the vibrational amplitude approached a critical point, and the liquid surface broke up into tiny drops. The micro-droplets were are steadily and continuously formed after the liquid feeding rate was optimized. The simulation study reported a minimum vibrational amplitude or onset value of 0.38 μm at 500 kHz frequency. The required minimum energy to atomize the drops was simulated by COMSOL Multiphysics simulation software. The simulation result agreed well with the numerical results of a subharmonic vibrational model that ocurred at 250 kHz frequency on the liquid surface. This newly designed single frequency ultrasonic atomizer showed its true physical characteristic of resonance on the fluid surface plane. Hence, this research will contribute to the future development of a single-frequency ultrasonic nebulizer and mechatronics for the generation of uniform atomized droplets.
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Supriadi, Sugeng, Tsaome Indah Susimah, Muhammad Haekal Sena Akbar, Bambang Suharno, Ario Sunar Baskoro, and Dharmanto. "Designs and Evaluations of a Gas Atomizer to Fabricate Stainless Steel Metal Powder to Be Applied at a Metal Injection Molding." Key Engineering Materials 833 (March 2020): 40–47. http://dx.doi.org/10.4028/www.scientific.net/kem.833.40.
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Metal Injection Molding (MIM) is an application of Powder Metallurgy (PM) and Plastic Injection Molding currently being developed to produce precisely-small components. Most of the metal applications using PM are stainless steel fabricated by a gas atomizer. In this study, an atomizer is designed and fabricated to produce stainless steel powder by using a free fall gas atomization method. The stainless steel used in this study is AISI 304 atomized with the diameter sizes varying from about 3 mm, 5 mm, and 7 mm. The variables of diameter size results are the lowest melt flow rate produces the smallest mean diameter, but no significant difference on the sphericity of powder morphology. While the gas pressure variation results shows that metal powder with smaller size will be produced more using the high gas pressure. The gas atomizer have successfully produced metal powder with the size <40 μm and have a spherical shape. The well rounded sphericity for melt flowrate 0.41x10-3 m3/min, 1.14 x10-3 m3/min, and 2.24x10-3 m3/min are 60.0%, 36.0%, and 55.2% respectively.
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Si, Chao Run, Xian Jie Zhang, and Jun Biao Wang. "Processing and Microstructure Properties of 7055-Al Alloy Prepared by Low-Pressure Spray Forming." Applied Mechanics and Materials 574 (July 2014): 373–79. http://dx.doi.org/10.4028/www.scientific.net/amm.574.373.
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Spray forming is a new developed advanced metal-forming process, of which the property benefits from rapid solidification. The porosity produced during the atomization progress can obviously decrease the material performance. In this paper, a self-designed Laval-type atomizer is used to improve atomization efficiency. The atomization results show that the atomizer can obtain well atomization effect at a relative lower atomization pressure, and the mass median diameter d50 is 63.5μm and 43.4μm when the atomization gas pressure P0=0.4 and 0.8MPa separately. The technological parameters are optimized by overall considering the atomized droplet size, gas consumption, deposition property, and the metal yield. By the designed atomizer, the as-deposited billet with lower porosity content can be obtained with the technological parameters of the melting temperature T=800°C, atomization pressure P0=0.6MPa, and spray distance h=500mm. Further test with the deposited billet show that the grain size of the spray formed 7055-Al alloy is mainly ranging 10~30μm, which is about one third of that of as-cast billet.
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Wittner, Ballesteros, Link, Karbstein, and Gaukel. "Air-Core–Liquid-Ring (ACLR) Atomization Part II: Influence of Process Parameters on the Stability of Internal Liquid Film Thickness and Resulting Spray Droplet Sizes." Processes 7, no. 9 (September 10, 2019): 616. http://dx.doi.org/10.3390/pr7090616.
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Air-core–liquid-ring (ACLR) atomization presents a specific type of internal mixing pneumatic atomization. It can be used for disintegration of high viscous feed liquids into small droplets at relatively low gas consumptions. However, the specific principle of ACLR atomization is still under research and no guidelines for process and atomizer design are available. Regarding literature on pre-filming atomizers, it can be hypothesized for ACLR atomization that the liquid film thickness inside the exit orifice of the atomizer, as well as the resulting spray droplet sizes decrease with increasing air-to-liquid ratio (ALR) and decreasing feed viscosity. In this study, the time dependent liquid film thickness inside the exit orifice of the atomizer was predicted by means of computational fluid dynamics (CFD) analysis. Results were compared to high speed video images and correlated to measured spray droplet sizes. In conclusion, the hypothesis could be validated by simulation and experimental data, however, at high viscosity and low ALR, periodic gas core breakups were detected in optical measurements. These breakups could not be predicted in CFD simulations, as the simplification of an incompressible gas phase was applied in order to reduce computational costs and time. Nevertheless, the presented methods show good potential for improvement of atomizer geometry and process design as well as for further investigation of the ACLR atomization principle.
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Wittner, Marc, Heike Karbstein, and Volker Gaukel. "Air-Core-Liquid-Ring (ACLR) Atomization: Influences of Gas Pressure and Atomizer Scale Up on Atomization Efficiency." Processes 7, no. 3 (March 6, 2019): 139. http://dx.doi.org/10.3390/pr7030139.
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Air-core-liquid-ring (ACLR) atomizers present a specific type of internal mixing pneumatic atomizers, which can be used for efficient atomization of high viscous liquids. Generally, atomization efficiency is considered as a correlation between energy input and resulting droplet size. In pneumatic atomization, air-to-liquid ratio by mass (ALR) is commonly used as reference parameter of energy input. However, the pressure energy of the atomization gas is not considered in the calculation of ALR. In internal mixing ACLR atomizers, it can be assumed that this energy contributes to liquid disintegration by expansion of the gas core after exiting the atomizer. This leads to the hypothesis that droplet sizes decrease with increasing gas pressure at constant ALR. Therefore, the use of volumetric energy density (EV) as a reference parameter of energy input was investigated at different gas pressures between 0.4 and 0.8 MPa. Furthermore, scale up-related influences on the atomization efficiency of ACLR atomization were investigated by use of an atomizer with enlarged exit orifice diameter. We can conclude that EV can be applied as a reference parameter of ACLR atomization processes with different gas pressures. However, within the range investigated no clear influence of gas pressure on atomization efficiency was found. Up-scaling of ACLR atomizers allows production of similar droplet sizes, but atomization efficiency decreases with increasing exit orifice diameter.
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Liao, Y., A. T. Sakman, S. M. Jeng, M. A. Jog, and M. A. Benjamin. "A Comprehensive Model to Predict Simplex Atomizer Performance." Journal of Engineering for Gas Turbines and Power 121, no. 2 (April 1, 1999): 285–94. http://dx.doi.org/10.1115/1.2817119.
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The pressure swirl atomizer, or simplex atomizer, is widely used in liquid fuel combustion devices in the aerospace and power generation industries. A computational, experimental, and theoretical study was conducted to predict its performance. The Arbitrary-Lagrangian-Eulerian method with a finite-volume scheme is employed in the CFD model. Internal flow characteristics of the simplex atomizer, as well as its performance parameters such as discharge coefficient, spray angle and film thickness, are predicted. A temporal linear stability analysis is performed for cylindrical liquid sheets under three-dimensional disturbances. The model incorporates the swirling velocity component, finite film thickness and radius that are essential features of conical liquid sheets emanating from simplex atomizers. It is observed that the relative velocity between the liquid and gas phases, density ratio and surface curvature enhance the interfacial aerodynamic instability. The combination of axial and swirling velocity components is more effective than only the axial component for disintegration of liquid sheet. For both large and small-scale fuel nozzles, mean droplet sizes are predicted based on the linear stability analysis and the proposed breakup model. The predictions agree well with experimental data at both large and small scale.
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Eslamian, Morteza, and Nasser Ashgriz. "Effect of Atomization Method on the Morphology of Spray-Generated Particles." Journal of Engineering Materials and Technology 129, no. 1 (September 8, 2006): 130–42. http://dx.doi.org/10.1115/1.2400270.
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Effect of various atomization methods and solute concentration on the morphology of spray dried magnesium sulphate particles is investigated. Four types of atomizers are characterized and tested including (i) a vibrating mesh nebulizer, (ii) a splash plate nozzle, (iii) an air mist atomizer, and (iv) a pressure atomizer. Several types of particle morphologies are identified in this research. Spray characteristics, such as droplet number density, droplet size, and velocity, and accompanying atomizing air have major influence on the drying and morphology of the particles. High initial solute concentrations result in the formation of thick-walled particles, and this prevents the particles to burst. It is found to be difficult to obtain fully filled magnesium sulphate particles, even for saturated solutions at room temperature because the solution equilibrium saturation changes substantially with temperature.
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Reed, Joseph P., Franklin R. Hall, and Donald L. Reichard. "Influence of Atomizers Upon Efficacy of Tridiphane plus Atrazine Applied Postemergence." Weed Technology 4, no. 1 (March 1990): 92–96. http://dx.doi.org/10.1017/s0890037x00025057.
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Field studies with flatfan, twinjet, flood and rotary atomizers were conducted in 1987 and 1988. The results indicated that tridiphane at 0.6 kg ai/ha plus atrazine at 1.7 kg ai/ha with 2.0 L/ha of soybean oil adjuvant was more effective in controlling giant foxtail and common lambsquarters when applied by the flatfan, twinjet, and rotary atomizers. Image analysis indicated that weed control by a postemergence herbicide was generally enhanced by better application coverage. Droplet size measurement by phase droplet particle/droplet analyzer demonstrated that the rotary atomizer produced a narrower range of droplet diameters between the Dv.1and Dv.9volumes than any of the other atomizers.
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Raunmiagi, Zygmunt, and Piotr Bielawski. "Identification of the Water-Cooled Fuel Injectors for Engines." Key Engineering Materials 588 (October 2013): 134–39. http://dx.doi.org/10.4028/www.scientific.net/kem.588.134.
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The fuel injector acts a double role: it is the valve of the pump supplying fuel to the combustion chamber and the device spraying a supplied dose. As the valve it may operate as a self-opening or self-closing valve, depending on the pressure produced by the fuel pump, or the valve controlled by external signals. Techniques and diagnosis methods for fuel injectors depend on a fuel injectors control system and construction details. For practical reasons the fuel injector is a sectional valve with a separated component called atomizer. Atomizers must be cooled. It is possible to cool with fuel or with external water-or oil-cooling system. In case of liquid-cooled fuel injectors, apart from malfunctions causes known from literature, decrease of the cooling efficiency may appear, as the effect of the penetration of fuel from injector to the cooling system of injector. There are no reports concerning detectability of fuel leakage into cooling liquid with known techniques and diagnosis methods of injection systems and fuel injectors. In the article there will be presented as follows: a connection of the atomizer and injector body as the place of fuel leakage into the cooling system, reasons for loss of leak tightness in connection of atomizer with the body of atomizer and methods applicable for the leak tightness analysis, mechanisms of injectors malfunction caused by the loss of leak tightness. The analysis of applied and possible methods of injectors diagnosis in the aspect of identification of said leakiness will be carried out.
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Mlkvik, Marek, and Branislav Knizat. "On the spray pulsations of the effervescent atomizers." EPJ Web of Conferences 180 (2018): 02069. http://dx.doi.org/10.1051/epjconf/201818002069.
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The presented paper focuses on the comparison of the two effervescent atomizer configurations—the outside-in-gas (OIG) and the outside-in-liquid (OIL). The comparison was based on the spray pulsation assessment by different methods. The atomizers were tested under the same operating conditions given by the constant injection pressure (0.14 MPa) and the gas to the liquid mass ratio (GLR) varying from 2.5 to 5%. The aqueous maltodextrin solution was used as the working liquid (μ = 60 and 146 mPa·s). We found that the time-averaging method does not provide sufficient spray quality description. Based on the cumulative distribution function (CDF) we found that the OIG atomizer generated the spray with non-uniform droplet size distribution at all investigated GLRs. Exceptionally large droplets were present even in the spray which appeared stable when was analyzed by the time-averaging method.
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Czernek, Krystian, Michał Hyrycz, Andżelika Krupińska, Magdalena Matuszak, Marek Ochowiak, Stanisław Witczak, and Sylwia Włodarczak. "State-of-the-Art Review of Effervescent-Swirl Atomizers." Energies 14, no. 10 (May 16, 2021): 2876. http://dx.doi.org/10.3390/en14102876.
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This paper presents issues in the field of theory, construction, calculations, as well as the design of effervescent-swirl atomizers. The results of experimental studies of spraying liquids with different physico-chemical properties for this type of atomizers are discussed. Effervescent-swirl atomization is a complex process and its mechanism is not fully understood. Therefore, the purpose of the manuscript is the complexity of the atomization process and its mechanism as well as the influence of individual parameters on its efficiency were thoroughly analyzed. The analyzed parameters include: atomizer design, outlet shape, gas and liquid flow rate, injection pressure, physicochemical properties of the atomized liquid, pressure drop, outflow coefficient, spray angle, quantitative droplet distributions, and average droplet diameter. Moreover, in the work, on the basis of the literature review, the results of the research related to, inter alia, the phenomenon of air core formation and the influence of a number of parameters on the efficiency of the atomization process are analyzed. The literature review included in the work makes it possible to better understand the atomization process carried out in effervescent-swirl atomizers, and also provides better design criteria and analysis of the efficiency of the tested devices. The article presents correlation equations covering the basic features of the atomization process, which relate a large number of parameters influencing the efficiency of this process and the character of the sprayed liquid, which may be useful in design practice.
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Malý, Milan, Marcel Sapík, Jan Jedelský, Lada Janáčková, Miroslav Jícha, Jaroslav Sláma, and Graham Wigley. "Internal flow characteristics in scaled pressure-swirl atomizer." EPJ Web of Conferences 180 (2018): 02059. http://dx.doi.org/10.1051/epjconf/201818002059.
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Pressure-swirl atomizers are used in a wide range of industrial applications, e.g.: combustion, cooling, painting, food processing etc. Their spray characteristics are closely linked to the internal flow which predetermines the parameters of the liquid sheet formed at the discharge orifice. To achieve a better understanding of the spray formation process, the internal flow was characterised using Laser Doppler Anemometry (LDA) and high-speed imaging in a transparent model made of cast PMMA (Poly(methyl methacrylate)). The design of the transparent atomizer was derived from a pressure-swirl atomizer as used in a small gas turbine. Due to the small dimensions, it was manufactured in a scale of 10:1. It has modular concept and consists of three parts which were ground, polished and bolted together. The original kerosene-type jet A-1 fuel had to be replaced due to the necessity of a refractive index match. The new working liquid should also be colourless, non-aggressive to the PMMA and have the appropriate viscosity to achieve the same Reynolds number as in the original atomizer. Several liquids were chosen and tested to satisfy these requirements. P-Cymene was chosen as the suitable working liquid. The internal flow characteristics were consequently examined by LDA and high-speed camera using p-Cymene and Kerosene-type jet A-1 in comparative manner.
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Panatarani, Camellia, Dunden Gilang Muharam, Bambang Mukti Wibawa, and I. Made Joni. "Blue Luminescent of ZnO:Zn Nanocrystal Prepared by One Step Spray Pyrolysis Method." Materials Science Forum 737 (January 2013): 20–27. http://dx.doi.org/10.4028/www.scientific.net/msf.737.20.
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A blue luminescent of ZnO:Zn nanocrystal has been successfully prepared by one step spray pyrolysis method without reducing gas atmosphere. Zinc acetate dihydrate aqueous solutions (0.05 M) were atomized by ultrasonic atomizer. The atomizer used an air as carrier gas with 1, 3 and 5 L/min flowrate. The tubular reactor was set at 500, 600 and 700oC. As prepared samples were characterized by means of x-ray diffraction spectroscopy and scanning electron microscope-energy dispersive x-ray spectroscopy (SEM-EDS). The crystal size of as prepared particles calculated by Scherrer’s equation give 10-20 nm. The luminescent properties of as prepared particles were measured using spectrofluorophotometer. The highest photoluminescent intensity of particles irradiated with excited wavelength of 250 nm was obtained from samples prepared using 5 L/min carrier gas with temperature of tubular reactor 700oC. High intensity of blue luminescent was obtained due to oxygen vacancy in ZnO:Zn.
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Guo, Zhengyan, Yi Jin, Kai Zhang, Kanghong Yao, Yunbiao Wang, Di Wu, Xiaomin He, and Mei Zheng. "Effect of Low Ambient Pressure on Spray Cone Angle of Pressure Swirl Atomizer." International Journal of Aerospace Engineering 2021 (June 23, 2021): 1–10. http://dx.doi.org/10.1155/2021/5539231.
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Pressure swirl atomizers are widely used in gas turbine combustor; this paper is aimed at researching the effect of low ambient pressure (0.1 MPa to 0.01 MPa, lower than an atmosphere) on the spray cone angle of pressure swirl atomizer. The spray angle is captured by high-speed photography; then, an image post program is used to process the spray angle magnitude. A mathematical model of a single droplet’s movement and trajectory based on force analysis is proposed to validate the spray angle variation. The maximum variation of the spray cone angle, which is observed when fuel supply pressure drop through the atomizer is 1 MPa as the ambient pressure decreases from 0.1 MPa to 0.01 MPa, is found to be 23.9%. The experimental results show that the spray cone angle is expected to increase with the ambient pressure decrease; meanwhile, mathematical results agree well with this trend.
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Mlkvik, Marek. "Unsteady Behaviour of the Effervescent Atomizer." MATEC Web of Conferences 328 (2020): 01008. http://dx.doi.org/10.1051/matecconf/202032801008.
Full textAbstract:
The effervescent atomizer is a well-established type of the twin-fluid nozzle with internal mixing of fluids. It is popular for the ability to process highly viscous liquids, such as liquid fuels, into a fine spray with low gas consumption. This study aims to investigate the performance of the effervescent nozzle when spraying the liquids with a viscosity up to 308 mPa·s. The working parameters of the nozzle were defined by the mass flows ratio of the gas to the liquid (GLR =2.5 to 20 %) and the gas pressure at the nozzle inlet (Δp = 0.14 MPa). The spray quality was investigated by the laser diffraction system, measuring the spray drop sizes. The investigated nozzle was able to atomize all of the model liquids. However, the liquid viscosity increase led to the need to operate the nozzle with the larger gas consumption. The minimum GLR for the spraying of the liquid with the viscosity 308 mPa·s was 10 %, while the less viscous liquid (60 mPa·s) was processed with the GLR = 2.5 %. It was observed that the spray quality was, at the low GLRs, lowered by unstable nozzle work, caused by the presence of the plug flow in the mixing chamber of the atomizer.
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Kahraman, Mehmet, Guven Komurgoz, and Ibrahim Ozkol. "Numerical Analysis of Pressure Swirl Atomizer." Applied Mechanics and Materials 798 (October 2015): 190–94. http://dx.doi.org/10.4028/www.scientific.net/amm.798.190.
Full textAbstract:
Atomization quality of liquids has a great importance on the performance of combustion engines. In this study the internal flow phenome of pressure swirl atomizer is investigated by using numerical method. The design of swirl atomizer is performed based on the requested atomizer characteristics which are sauter mean diamer (SMD), spray cone angle and break up length. Prediction and understanding of liquid film dynamics in the atomizer inside are the fundamental ways to explore atomizer performance. The purpose of this study is to estimate the air core size and film thickness in pressure swirl atomizer by setting single phase numeric computations. This article concludes that the CFD validated swirl atomizer design can be achieved with the lower computational cost using stream function methodology.