Algorithm Analysis of Gas Bubble Generation in a Microfluidic Device

2019 ◽  
Vol 13 (2) ◽  
pp. 133-141
Author(s):  
Jang Ho Ha ◽  
Hirak Mazumdar ◽  
Tae Hyeon Kim ◽  
Jong Min Lee ◽  
Jeong-Geol Na ◽  
...  
Keyword(s):  
Microfluidic Device ◽  
Algorithm Analysis ◽  
Gas Bubble ◽  
Bubble Generation

scholarly journals Interfacial Tension Sensor for Low Dosage Surfactant Detection

2021 ◽  
Vol 5 (1) ◽  
pp. 9
Author(s):  
Piotr Pawliszak ◽  
Bronwyn H. Bradshaw-Hajek ◽  
Christopher Greet ◽  
William Skinner ◽  
David A. Beattie ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Microfluidic Device ◽  
Profile Analysis ◽  
Simple Method ◽  
Bubble Generation ◽  
Flotation Process ◽  
Line Measurement ◽  
Tension Sensor ◽  
Low Dosage

Currently there are no available methods for in-line measurement of gas-liquid interfacial tension during the flotation process. Microfluidic devices have the potential to be deployed in such settings to allow for a rapid in-line determination of the interfacial tension, and hence provide information on frother concentration. This paper presents the development of a simple method for interfacial tension determination based on a microfluidic device with a flow-focusing geometry. The bubble generation frequency in such a microfluidic device is correlated with the concentration of two flotation frothers (characterized by very different adsorption kinetic behavior). The results are compared with the equilibrium interfacial tension values determined using classical profile analysis tensiometry.

Generation and Transport of Bubbles in a Microfluidic Device

2008 ◽  
Author(s):  
Renqiang Xiong ◽  
Jacob N. Chung
Keyword(s):  
Silicon Wafer ◽  
Microfluidic Device ◽  
High Speed ◽  
Micro Channel ◽  
Bubble Generation ◽  
Air Bubble ◽  
Micro Scale ◽  
Bubble Transport

In this paper we used high speed recording to characterize segmented micro-scale air bubble generation in a T-junction and bubble transport in a serpentine micro-channel fabricated in a standard silicon wafer.

Laboratory Results of Cleaning Produced Water by Gas Flotation

1980 ◽  
Vol 20 (03) ◽  
pp. 175-190 ◽  
Author(s):  
W.T. Strickland
Keyword(s):  
Bubble Size ◽  
Contact Process ◽  
Gas Bubbles ◽  
Small Scale ◽  
Supersaturated Solution ◽  
Gas Bubble ◽  
Laboratory Studies ◽  
Bubble Generation ◽  
Gas Concentration ◽  
Attachment Efficiency

Abstract Laboratory studies were conducted to determine the factors governingflotation-cell performance. It was learned that oil removal is increased byincreasing collision and attachment efficiencies and gas/liquid contact time.Collision efficiency is increased by increasing oil-drop size and gasconcentration and by decreasing gas-bubble size. Several factors (crude type, pH, temperature, etc.) were found to change attachment efficiency. Nocorrelation between basic system properties and attachment efficiency wasfound. Some of these important parameters are determined by the cell design, whereas others are characteristics of the feed. Thus, the same type (design)cell will produce different effluent oil concentrations for different feeds.Also, the effluent from a given cell will change when the feed characteristicschange. Introduction Flotation cells are used widely throughout industry to remove oil fromoil/water mixtures produced from underground reservoirs. This is becauseflotation cells have proved to be a practical and reliable means of oilremoval. Small-scale pilot tests have been attempted to predict the performanceof a full-scale unit, but these have not been too successful. Therefore, laboratory studies were initiated to increase the knowledge of this process.The process of flotation consists of four basic steps:bubble generation inoily water,contact between a gas bubble and an oil drop suspended in thewater,attachment of the oil drop to the gas bubble, andrising of thegas/oil combination to the water surface where the oil can be removed byskimming. Research was conducted to investigate these basic steps and todetermine the fundamental mechanisms and parameters that govern the process.Both the theoretical and experimental results are discussed in this paper. Theory Bubble Generation There are three common methods of bubble generation:dissolution of gasfrom a supersaturated solution (dissolved gas flotation),mechanical mixingof gas and liquid (dispersed gas flotation), anddirect gas injection bymeans of a sparger. The method of bubble generation and important because itdetermines the bubble size and gas concentration for a given feed. As shown inthe section on bubble-drop contact, bubble size and gas concentration influencethe collision efficiency and, thus, the rate of oil recovery. Bubble/Drop Contact Gas bubbles and oil drops must come into contact for flotation to occur.This contact process is basically one of hydrodynamics. Since both oil and gasare less dense than water (with the exception of a few very heavy crudes), theyboth tend to rise relative to water. Gas bubbles are generally larger than oildrops (gas bubbles are usually larger than 100 m and oil drops in producedwater are usually smaller than 30 m), and the density difference between gasand water is much greater than between oil and water. For these two reasons, gas bubbles rise more rapidly than the oil drops and overtake them. This leadsto the possibility of bubble-drop contact. On the other hand, a fluid flowpattern is established around a moving gas bubble that tends to deflect oildrops, which reduces the possibility of contact. SPEJ P. 175

Modelling and State Estimation in Pulsed ECM with Variable Electrolyte Conductivity

2013 ◽  
Vol 554-557 ◽  
pp. 1910-1915
Author(s):  
Markus Boxhammer ◽  
Jin Ming Lu
Keyword(s):  
Process Model ◽  
Current Flow ◽  
Electrochemical Machining ◽  
Gap Size ◽  
Gas Bubble ◽  
Size Estimation ◽  
Input Output ◽  
Process Stability ◽  
Bubble Generation ◽  
Electrolyte Conductivity

In Pulsed Electrochemical Machining the control of the size of the process gap is necessaryto achieve process stability. However, the gap size cannot be measured directly during the machiningprocess. Based on an equivalent circuit, a process model has been derived for plane electrodes andconstant conductivity. In a previous study, an approach to controlling and estimating the gap size hasbeen introduced. By input-output-linearisation, a linear system was found, making it easier to controlthe gap size and current flow simultaneously.In this work the existing model is revised for its applicability to the conductivity change duringeach pulse resulting from heat and gas bubble generation. Depending on the particular moment of thecurrent measurement, the value of the conductivity in the electrolyte reservoir cannot be used for thegap size estimation directly. Three different approaches to overcome this problem are reviewed. Themost promising approach was implemented on a real-time platform and optimised for execution time.

Simulation of micro gas bubble generation of uniform diameter in an ultrasonic field by a boundary element method

2006 ◽  
Vol 18 (10) ◽  
pp. 108102 ◽  
Author(s):  
Toshinori Makuta ◽  
Fumio Takemura
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Ultrasonic Field ◽  
Gas Bubble ◽  
Bubble Generation ◽  
Uniform Diameter ◽  
Element Method

scholarly journals Hydraulic Study of Bubble Migration in Liquid Titanium Alloy Melt during Vertical Centrifugal Casting Process

2019 ◽  
Vol 38 (2019) ◽  
pp. 309-316
Author(s):  
Qin Xu ◽  
Xing Wang ◽  
Shiping Wu
Keyword(s):  
Centrifugal Casting ◽  
Gas Bubbles ◽  
Casting Process ◽  
Initial Position ◽  
Gas Bubble ◽  
Bubble Generation ◽  
Mould Wall ◽  
Line Parallel ◽  
Complex Cavity ◽  
Liquid Titanium

AbstractThe bubble migration in liquid titanium melt during vertical centrifugal casting process has been investigated by hydraulic experiments. Results show that the gas bubble in the simple cavity ultimately migrates like a line parallel to the wall in the opposite direction to the rotational casting mould. The deviation distance of the bubble in the simple geometry cavity tends to increase with the increment of the mould rotational speed during the migration process. And the gas bubble is much easier to migrate like a line when its initial position is nearer to the casting mould wall which is opposite to the mould rotational direction. The migration trajectories of bubbles located at different position in the complex cavity are more complicated than that in the simple cavity. The casting mould in the complex cavity can hamper both the radial movement and the circular movement of the bubble. And gas bubbles will gather, re-nucleate and form new bigger bubbles beside the casting mould wall. The re-formed gas bubbles in the complex cavity become bigger than which escape from bubble generation chamber.

scholarly journals Gas bubble generation at a micro-scale orifice

2007 ◽  
Author(s):  
Philippe Genereux
Keyword(s):  
Gas Bubble ◽  
Bubble Generation ◽  
Micro Scale

Microfluidic Device for the Determination of Water Chlorination Levels Combining a Fluorescent meso-Enamine Boron Dipyrromethene Probe and a Microhydrocyclone for Gas Bubble Separation

2019 ◽  
Vol 91 (20) ◽  
pp. 12980-12987 ◽  
Author(s):  
Adam Tillo ◽  
Juergen Bartelmess ◽  
Vraj P. Chauhan ◽  
Jérémy Bell ◽  
Knut Rurack
Keyword(s):  
Microfluidic Device ◽  
Gas Bubble ◽  
Bubble Separation ◽  
Boron Dipyrromethene ◽  
Water Chlorination

Bubble generation and transport in a microfluidic device with high aspect ratio

2009 ◽  
Vol 33 (8) ◽  
pp. 1156-1162 ◽  
Author(s):  
Renqiang Xiong ◽  
Jacob N. Chung
Keyword(s):  
Aspect Ratio ◽  
Microfluidic Device ◽  
High Aspect Ratio ◽  
Bubble Generation
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