Abstract
In this study, we report an experimental investigation into the bubble generation characteristics of a venturi-type ejector. A 5-mm-diameter vertically upwards nozzle placed in a 1-m3 water tank was used to generate bubbles at between 2 and 20 L/min airflow rate corresponding to a Reynolds number range of 1.7–17 × 103. High-speed photography and image analysis were used for bubble visualisation and feature extraction. An image processing algorithm was used to obtain bubble velocity profiles and size distribution. It was established that when the nozzle was placed at the ejector’s neck, high bubble velocities result, especially at large Reynolds numbers. Bubble size distributions were created, and size variability is strongly correlated with the gas Reynolds number as well as other liquid properties describing gas flow encountering a quiescent bulk liquid.
Graphical Abstract
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Akita K, Yoshida F (1974) Bubble size, interfacial area, and liquid-phase mass transfer coefficient in bubble columns. Ind Eng Chem Process De Dev 13(1):84–91. https://doi.org/10.1021/i260049a016
Al Ba’ba’a HB et al. (2016) Correlations of bubble diameter and frequency for air–water system based on orifice diameter and flow rate. J Fluids Eng 138(11):114501. [online]. http://fluidsengineering.asmedigitalcollection.asme.org/article.aspx?doi=10.1115/1.4033749
Azzopardi BJ, Hewitt GF (1997) Maximum drop sizes in gas-liquid flows. Multiph Sci Technol 9(2):109–204. [online]. http://www.dl.begellhouse.com/journals/5af8c23d50e0a883,5c0895136be4294a,5f75a5390381f451.html
Bhavaraju SM et al (1978) Bubble motion and mass transfer non-Newtonian fiuids: part I. Single bubble in power law and bingham fluids. AIChE J 24(6):1063–1070
Busciglio A et al (2008) Analysis of the bubbling behaviour of 2D gas solid fluidized beds: part I. Digital image analysis technique. Chem Eng J 140(1):398–413
Chatfield C (2004) The analysis of time series, an introduction, 6th edn. Chapman & Hall/CRC, New York
Datta RL et al (1950) The properties and behaviour of gas bubbles formed at a circular orifice. Trans Inst Chem Eng 28:14–26
Gabbard CH (1972) Development of a Venturi type bubble generator for use in the molten-salt reactor xenon removal system. Oak Ridge National Laboratory (ORNL), Oak Ridge
Gordiychuk A et al (2016) Size distribution and Sauter mean diameter of micro bubbles for a Venturi type bubble generator. Exp Therm Fluid Sci 70:51–60. https://doi.org/10.1016/j.expthermflusci.2015.08.014
Jamialahmadi M et al (2001) Study of bubble formation under constant flow conditions. Chem Eng Res Des 79(5):523–532. [online]. http://linkinghub.elsevier.com/retrieve/pii/S0263876201720783. Accessed 16 Dec 2016
Kantarci N et al (2005) Bubble column reactors. Process Biochem 40(7):2263–2283
Kim G et al (2012) Measurement of bubble diameter and rising velocity in a cylindrical tank using an optical fiber probe and a high speed visualization technique. J Korean Soc Vis 10(2):14–19. [online]. http://koreascience.or.kr/journal/view.jsp?kj=GSSGB0&py=2012&vnc=v10n2&sp=14
Kulkarni AA, Joshi JB (2005) Bubble formation and bubble rise velocity in gas–liquid systems: a review. Ind Eng Chem Res 44:5873–5931
Kumar A et al (1976) Bubble swarm characteristics in bubble columns. Can J Chem Eng 5:503–508
Laqua K et al. (2016) Methane bubble rise velocities under deep-sea conditions—influence of initial shape deformation. Colloids Surf A Physicochem Eng Asp 505:106–117. [online]. http://linkinghub.elsevier.com/retrieve/pii/S0927775716300413
Liu Z et al (2005) Study of bubble induced flow structure using PIV. Chem Eng Sci 60(13):3537–3552. [online]. http://www.sciencedirect.com/science/article/pii/S0009250905000709. Accessed 18 May 2017
Liu L et al (2016) Experimental studies on the terminal velocity of air bubbles in water and glycerol aqueous solution. Exp Therm Fluid Sci 78:254–265. [online]. http://linkinghub.elsevier.com/retrieve/pii/S089417771630156X
Marshall SH et al (1986) An initial study of air bubble formation from an orifice swept by transverse liquid flow. In: 9th Australasian fluid mechanics conference. 1986 Auckland, pp 391–394
Mizushima Y et al (2013) Measurement technique of bubble velocity and diameter in a bubble column via single-tip optical-fiber probing with judgment of the pierced position and angle. Chem Eng Sci 100:98–104. [online]. http://linkinghub.elsevier.com/retrieve/pii/S0009250913000596. Accessed 23 June 2016
Moo-Young M, Blanch HW (1981) Design of biochemical reactors mass transfer criteria for simple and complex systems. In: Reactors and reactions. Springer, Heidelberg, pp 1–69. [online]. http://dx.doi.org/10.1007/3-540-10464-X_16
Morris D et al (1987) Optical fiber probe to measure local void fraction profiles. Appl Opt 26(21):4660. [online]. https://www.osapublishing.org/abstract.cfm?URI=ao-26-21-4660
Murgan I et al (2017) Experimental PIV and LIF characterization of a bubble column flow. Flow Meas Instrum 54:224–235. [online]. http://www.sciencedirect.com/science/article/pii/S0955598617300468. Accessed 18 May 2017
Nogami S et al (2001) Nonlinear interaction between bubble generation and micro-convection. University of Tokyo
Pang M, Wei J (2013) Experimental investigation on the turbulence channel flow laden with small bubbles by PIV. Chem Eng Sci 94:302–315. [online]. http://linkinghub.elsevier.com/retrieve/pii/S0009250913001796. Accessed 30 June 2017
Sathe MJ et al (2010) Advanced PIV/LIF and shadowgraphy system to visualize flow structure in two-phase bubbly flows. Chem Eng Sci 65(8):2431–2442. [online]. http://linkinghub.elsevier.com/retrieve/pii/S000925090900815X. Accessed 30 June 2017
Terasaka K et al (2011) Development of microbubble aerator for waste water treatment using aerobic activated sludge. Chem Eng Sci 66(14):3172–3179
Theofanous TG, Sullivan J (1982) Turbulence in two-phase dispersed flows. J Fluid Mech 116(1):343. [online]. http://www.journals.cambridge.org/abstract_S0022112082000494. Accessed 17 May 2017
Tsuge H et al (1986) Bubble formation from a vertically downward facing nozzle in liquids and molten metals. J Chem Eng Jpn 19(4):326–330. [online]. http://joi.jlc.jst.go.jp/JST.Journalarchive/jcej1968/19.326?from=CrossRef
Wilkinson PM et al (1994) Mass transfer and bubble size in a bubble column under pressure. Chem Eng Sci 49(9):1417–1427
Yin J et al (2015) Experimental study on the bubble generation characteristics for an venturi type bubble generator. Int J Heat Mass Transf 91:218–224. https://doi.org/10.1016/j.ijheatmasstransfer.2015.05.076
Zhang L, Shoji M (2001) Aperiodic bubble formation from a submerged orifice. Chem Eng Sci 56(18):5371–5381
Zhang W, Zhu DZ (2013) Bubble characteristics of air–water bubbly jets in crossflow. Int J Multiph Flow 55:156–171. https://doi.org/10.1016/j.ijmultiphaseflow.2013.05.003
Zheng S et al (2010) Local bubble size distribution, gas–liquid interfacial areas and gas holdups in an up-flow ejector. Chem Eng Sci 65(18):5264–5271. [online]. http://linkinghub.elsevier.com/retrieve/pii/S0009250910003933. Accessed 10 July 2016
Ziegenhein T, Lucas D (2016) On sampling bias in multiphase flows: particle image velocimetry in bubbly flows. Flow Meas Instrum 48:36–41. [online]. http://www.sciencedirect.com/science/article/pii/S0955598616300103. Accessed 18 May 2017
Acknowledgements
This work is supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) through GCRC-SOP (No. 2011-0030013). This work was also supported by the New & Renewable Energy Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20151120100140). We also acknowledge the funding provided by the BK21 Plus Program of the School of Mechanical Engineering, Pusan National University, Republic of Korea.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Aliyu, A.M., Seo, H., Kim, M. et al. An experimental study on the characteristics of ejector-generated bubble swarms. J Vis 21, 711–728 (2018). https://doi.org/10.1007/s12650-018-0494-2
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12650-018-0494-2