Performance of Porous-Venturi Microbubble Generator for Aeration Process

Afisna, Lathifa Putri; Juwana, Wibawa Endra; Indarto, Indarto; Deendarlianto, Deendarlianto; Nugroho, Fellando Martino

doi:10.22219/jemmme.v2i2.5054

Cited by 5 publications

(3 citation statements)

References 8 publications

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“…The findings unravel the importance of optimizing operational parameters in obtaining the highest K L a (small bubbles). Most of the previous study on MBG put emphasis on the mechanics of microbubble formation and the bubble size dynamics [27,29,30,33]. Such information should be used as input for designing an energy efficient oxygenator that improves the performance of the current established systems.…”

Section: Aeration Effciencymentioning

confidence: 99%

Porous Venturi-Orifice Microbubble Generator for Oxygen Dissolution in Water

et al. 2020

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Microbubbles with slow rising speed, higher specific area and greater oxygen dissolution are desired to enhance gas/liquid mass transfer rate. Such attributes are very important to tackle challenges on the low efficiency of gas/liquid mass transfer that occurs in aerobic wastewater treatment systems or in the aquaculture industries. Many reports focus on the formation mechanisms of the microbubbles, but with less emphasis on the system optimization and assessment of the aeration efficiency. This work assesses the performance and evaluates the aeration efficiency of a porous venturi-orifice microbubble generator (MBG). The increment of stream velocity along the venturi pathway and orifice ring leads to a pressure drop (Patm > Pabs) and subsequently to increased cavitation. The experiments were run under three conditions: various liquid velocity (QL) of 2.35–2.60 m/s at fixed gas velocity (Qg) of 3 L/min; various Qg of 1–5 L/min at fixed QL of 2.46 m/s; and free flowing air at variable QLs. Results show that increasing liquid velocities from 2.35 to 2.60 m/s imposes higher vacuum pressure of 0.84 to 2.27 kPa. They correspond to free-flowing air at rates of 3.2–5.6 L/min. When the system was tested at constant air velocity of 3 L/min and under variable liquid velocities, the oxygen dissolution rate peaks at liquid velocity of 2.46 m/s, which also provides the highest volumetric mass transfer coefficient (KLa) of 0.041 min−1 and the highest aeration efficiency of 0.287 kgO2/kWh. Under free-flowing air, the impact of QL is significant at a range of 2.35 to 2.46 m/s until reaching a plateau KLa value of 0.0416 min−1. The pattern of the KLa trend is mirrored by the aeration efficiency that reached the maximum value of 0.424 kgO2/kWh. The findings on the aeration efficiency reveals that the venturi-orifice MBG can be further optimized by focusing on the trade-off between air bubble size and the air volumetric velocity to balance between the amount of available oxygen to be transferred and the rate of the oxygen transfer.

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Section: Aeration Effciencymentioning

confidence: 99%

Porous Venturi-Orifice Microbubble Generator for Oxygen Dissolution in Water

et al. 2020

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“…Microbubbles possess many advantages, such as large surface area, fast dissolution rate, excellent surface adsorption, long residence time in water, and negative charge properties. And microbubbles have extensive application prospects in chemical industry, 2,3 wastewater treatment, 4,5 fish farming, 6 food technology, 7 pharmaceutical industry, 8 microalgae thickening, 9 mineral engineering, 10 and degradation of organic pollutants, 11 etc. The device used for microbubble generation is called bubble generator.…”

Section: Introductionmentioning

confidence: 99%

A visualized investigation of bubble breakup in a swirl‐venturi bubble generator

Bie

Xue

et al. 2022

AIChE Journal

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The dynamics and breakup of bubbles in swirl-venturi bubble generator (SVBG) are explored in this work. The three-dimensional movement process and breakup phenomena of bubbles are captured by one high-speed camera system with two cameras while the distribution of swirling flow field is recorded through Particle Image Velocimetry technology. It is revealed that bubbles have two motion trajectories, which are deeply related to bubble breakup. One trajectory is that mother bubble moves upward in an axial direction of the SVBG to the diverging section, and the other trajectory is that mother bubble rotates obliquely upward to another side-wall along the radial direction. Meanwhile, binary breakup, shear-off-induced breakup, static erosive breakup, and dynamic erosive breakup are observed. For relatively high liquid Reynolds number, vortex flow regions are extended and the bubble size is reduced. Furthermore, it is worth noting that the number of microbubbles increases significantly for intensive swirling flow.

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“…Recently, however, lower powered microbubble generators have been developed. Modern developments include microbubble generators such as those produced by spherical bodies (Sadatomi et al, 2005), orifice plates (Sadatomi et al, 2012), venturis (Deendarlianto et al, 2017), membranes (Kukuzaki et al, 2010;Liu et al, 2012;Liu et al, 2013) and fluidic oscillators (Al-Mashhadani et al, 2015;Hanotu et al, 2016;Hanotu et al, 2017;Kamaroddin et al, 2016;Kamaroddin et al, 2020;Zimmerman et al, 2011a). These types of microbubble generator utilize a restriction in the fluid flow to cause a pressure drop and an automatic suction of gas (Parmar and Majumder, 2013).…”

Section: Introductionmentioning

confidence: 99%

Microbubbles and their application to ozonation in water treatment: A critical review exploring their benefit and future application

John

Brookes

Carra

et al. 2020

Critical Reviews in Environmental Science and Technology

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Ozonation is a widely applied water treatment process, used for oxidation of contaminants, as well as for the disinfection of water. However, the conventional ozonation process demands a high energy requirement and deep tanks to ensure effective mass transfer and oxidation.Microbubble technologies have emerged which have the potential to improve gas-liquid contacting. Microbubbles have diameters of 1-100 µm, while conventional bubbles used in ozonation are between 2 -6 mm. Microbubbles have many favorable characteristics that make them suitable for ozonation. In this review, the attributes of microbubbles for ozonation have been compared with those of conventional bubbles. The higher interfacial area and lower rise velocity of microbubbles compared with conventional bubbles means that ozone in the gas phase can be more efficiently transferred into the liquid phase. This is due to a higher contact time and increased contact area of the bubble with the bulk liquid. The analysis reveals that the volumetric mass transfer coefficient can be significantly enhanced through the use of microbubbles. In addition, the steady state dissolved ozone concentration was positively impacted by the use of microbubbles. Microbubbles were shown to be able to oxidize a broader range of organic compounds more quickly than for conventional bubbles. However, the review highlighted that comparison of microbubbles with conventional bubbles is not always carried

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Performance of Porous-Venturi Microbubble Generator for Aeration Process

Cited by 5 publications

References 8 publications

Porous Venturi-Orifice Microbubble Generator for Oxygen Dissolution in Water

Porous Venturi-Orifice Microbubble Generator for Oxygen Dissolution in Water

A visualized investigation of bubble breakup in a swirl‐venturi bubble generator

Microbubbles and their application to ozonation in water treatment: A critical review exploring their benefit and future application

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