Digital imaging measurement of dense multiphase flows in industrial processes

Honkanen, Markus; Eloranta, H.; Saarenrinne, Pentti

doi:10.1016/j.flowmeasinst.2009.11.001

Cited by 64 publications

(43 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…They are widely used for dense multiphase flows in industrial processes and in microstructures as well, for example for biological cell counting and sizing [6][7][8][9][10][11]. In addition to complex and expensive equipments, the main disadvantage of these techniques is their dependence on the visibility of the measurement volume and on the focal distance.…”

Section: Introductionmentioning

confidence: 99%

In-situ particle sizing at millimeter scale from electrochemical noise: simulation and experiments

Yakdi

Huet

Ngo

2015

Electrochimica Acta

View full text Add to dashboard Cite

Over the last few years, particle sizing techniques in multiphase flows based on optical technologies emerged as standard tools but the main disadvantage of these techniques is their dependence on the visibility of the measurement volume and on the focal distance. Thus, it is important to promote alternative techniques for particle sizing, and, moreover, able to work in hostile environment. This paper presents a single-particle sizing technique at a millimeter scale based on the measurement of the variation of the electrolyte resistance (ER) due to the passage of an insulating sphere between two electrodes immerged in a conductive solution. A theoretical model was proposed to determine the influence of the electrode size, the interelectrode distance, the size and the position of the sphere, on the electrolyte resistance. Experimental variations of ER due to the passage of spheres and measured by using a home-made electronic device are also presented in this paper. The excellent agreement obtained between the theoretical and experimental results allows validation of both model and experimental measurements. In addition, the technique was shown to be able to perform accurate measurements of the velocity of a ball falling in a liquid.

show abstract

Section: Introductionmentioning

confidence: 99%

In-situ particle sizing at millimeter scale from electrochemical noise: simulation and experiments

Yakdi

Huet

Ngo

2015

Electrochimica Acta

View full text Add to dashboard Cite

show abstract

“…For better development of applied methods used in prediction and optimization of engineering flows a deep understanding of underlying flow phenomena is crucial. Nevertheless it is known that obtaining knowledge on complex multiphase flows occurring in industrial processes [1] is often a challenging task where both numerical simulations and experimental investigations can be very demanding.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of multiphase flow in a model gearbox

Chernoray

Jahanmiri

2011

WIT Transactions on Engineering Sciences

View full text Add to dashboard Cite

This study concerns dynamics of a two-phase flow around a rotating solid body. Under consideration is a model of a gear wheel in a gearbox which rotates and is partially submerged in oil. The flow of interest is complex and involves effects of free surface dynamics, rotation, and formation of bubbles and drops. Occurring flow regimes include laminar, transitional and turbulent. The major focus of the investigation is on details of the developed flow, and the purpose is validation of numerical methods developed for design and optimization of such components. Current experiments are performed in a test rig which is modelling a generic simplified gearbox with a single isolated rotating wheel. The flow measurements are carried out by using particle image velocimetry (PIV) and the test rig is specially designed for this purpose with the optical access maximized. The flow similarity with respect to a real gearbox is fully maintained and the working fluid is a transparent mineral oil. The PIV measurements are performed at four different rotation speeds for two different wheel configurations in order to cover a spectrum of operational conditions needed for numerical modelling. The emphasis is on the result of experiments on a smooth wheel. The measurements are providing velocity distribution around the wheel and details on bubble and drop distribution.

show abstract

“…Local gas holdup had been measured by Kumara et al (2010), who performed the phase Doppler anemometry. Honkanen et al (2010) employed a digital camera to obtain images of bubbles during agitation, and utilized image analysis software to find that the bubble size in transitional flow was bigger than that in turbulent flow at the same We number. Laakkonen et al (2007) analyzed digital photographs to measure local bubble size distributions from Rushton turbine agitation, and unknown parameters of breakage and coalescence models were modified by experimental data.…”

Section: Introductionmentioning

confidence: 99%

Simulation of the Bubble Behaviors for Gas–Liquid Dispersion in Agitated Vessel

Liu

Sheng

Han

et al. 2017

J. Chem. Eng. Japan / JCEJ

View full text Add to dashboard Cite

The present study mainly investigates bubble behaviors in an agitated vessel. Computational uid dynamics provides a method for exploring the complex uid ow in an agitated vessel. A stirred tank model with transport equation for the interfacial area concentration and force equilibrium equation for bubbles under multi-forces is created for a 43-dm 3 agitated vessel. The model considers the breakage and coalescence mechanism of the bubbles. The local gas holdup is measured by ber-optical probe. After this, the bubble size distributions are calculated by the interfacial area concentration model. The simulations with validated models show good agreement with the experiments. From the simulation results, the area in which the gas holdup value is greater than 0.01 extends 37% in the upper circulation region when the rotation speed is increased to 40 rad/s from 20 rad/s. However, in the lower circulation, the gas holdup maintains a low level due to the existence of a "death zone". The simulations indicate that the bubble breakage mainly occurs in the impeller out ow region and the coalescence occurs in the upper circulation region. For bubble behaviors being in the lower circulation region, bubble coalescence or breakage is determined by the ow eld pattern in the vessel. Moreover, it is di cult for the simulation process to converge when the virtual mass force is considered and there is a lack of effective technology to measure it, which has led researchers to generally ignore this force. In order to analyze the virtual mass force, the present study utilizes computer programming which is based on the virtual mass force formula to obtain the force. The results show that at positions close to the impeller tip and the center of the upper region, the virtual mass force value is 0.015 and 0.017, respectively, but the value is approximately zero in the bulk of the tank. Hence, the bubble has two signi cant stages of acceleration process in the vessel.

show abstract

Digital imaging measurement of dense multiphase flows in industrial processes

Cited by 64 publications

References 14 publications

In-situ particle sizing at millimeter scale from electrochemical noise: simulation and experiments

In-situ particle sizing at millimeter scale from electrochemical noise: simulation and experiments

Experimental study of multiphase flow in a model gearbox

Simulation of the Bubble Behaviors for Gas–Liquid Dispersion in Agitated Vessel

Contact Info

Product

Resources

About