Atomization of Liquids by Two-phase Gas-liquid Flow through a Plain-orifice Nozzle: Flow Regimes inside the Nozzle

Abstract

Liquids or suspensions are divided into sprays of small droplets by atomization of two‐phase gas‐liquid mixtures. In this way either an equal distribution of the droplets or the generation of large surface areas of the liquid phase are accomplished, leading to increased heat‐ and mass‐transfer. The spatial and time dependency of the mean droplet diameter is a function of the total pressure upstream of the nozzle, the volumetric flow rate of the liquid and the gas, as well as on the flow regime in the nozzle. Thus the radial and axial profile of the void fraction inside the nozzle are measured with an electrical measurement technique. In addition, the flow in the nozzle is imaged by a high‐speed camera. Three flow regimes are identified. These are bubbly flow, plug flow and annular flow. A continuous flow of the emitting spray is observed for bubbly flow and annular flow only. The distribution of the dispersed bubble phase is given by ratio of the isothermic compression energy needed to pressurize the gas mass flow rate from atmospheric pressure up to the total pressure in front of the nozzle, and the potential energy of the supplied liquid mass flow rate.

Monolithic microfluidic mixing–spraying devices for time-resolved cryo-electron microscopy

“…fuel combustion, thin film coating, sprinkling, and powdering. Various nozzle types, based on spraying mechanism, have been developed, such as one phase (liquid) high pressure supersonic jets (Pianthong et al, 2003), ultrasonic spray (Rajan and Pandit, 2009), electrospray (Deng et al, 2007), and two phase (liquid/gas) internal or external atomization (Butler et al, 2002; Cavaliere et al, 2003; Jazayeri and Li, 2000; Kufferath et al, 1999; Lörcher and Mewes, 2001). The dimension of macro-scale spray nozzles usually ranges from several millimeters down to less than a millimeter, and the sizes of the generated droplets are in the range of tens of micrometers to greater than one millimeter.…”

Niederdruck‐Zerstäuben von Flüssigkeiten an Sieben

“…Die Abscheidung soll bei Temperaturen von bis zu 1400 C erfolgen, weshalb sich derzeit nur Schüttschichtfilter mit keramischen Füllkörpern als Abscheider anbieten [1]. Solche Schüttschichtfilter werden aufgrund ihrer mechanischen und chemischen Beständig- …”

Experimental Investigation of Effervescent Atomization, Part Ii: Internal Flow and Spray Characterization With Novel Darpa Suboff Afterbody Streamline Aerator

“…Second, the visualization of stabilized gas-liquid flow in the mixing chamber. The results of internal flow visualizations are usually quantified by categorising the internal flow behaviour (both at the aerator orifice and in the mixing chamber) into flow regimes (Catlin and Swithenbank, 2001;Kim and Lee, 2001;Lörcher et al, 2005;Jobedhar, 2014;Hampel et al, 2009;Huang et al, 2008;Jedelsky and Jicha, 2013;Sun et al, 2015;Gomez, 2010;Stähle et al, 2015b;Lörcher and Mewes, 2001;Liu et al, 2010;Hang et al, 2014), with some researchers extending this analysis to produce flow maps (Kim and Lee, 2001;Huang et al, 2008;Lörcher and Mewes, 2001;Hang et al, 2014).…”