In-line mixing states monitoring of suspensions using ultrasonic reflection technique.

Based on the measurement of echo signal changes caused by different concentration distributions in the mixing process, a simple ultrasonic reflection technique is proposed for in-line monitoring of the mixing states of suspensions in an agitated tank in this study. The relation between the echo signals and the concentration of suspensions is studied, and the mixing process of suspensions is tracked by in-line measurement of ultrasonic echo signals using two ultrasonic sensors. Through the analysis of echo signals over time, the mixing states of suspensions are obtained, and the homogeneity of suspensions is quantified. With the proposed technique, the effects of impeller diameter and agitation speed on the mixing process are studied, and the optimal agitation speed and the minimum mixing time to achieve the maximum homogeneity are acquired under different operating conditions and design parameters. The proposed technique is stable and feasible and shows great potential for in-line monitoring of mixing states of suspensions.

[1]  Extent of mixing in a two-component batch system measured using MRI , 2001 .

[2]  Michael T. Hicks,et al.  CLOUD HEIGHT IN SOLIDS SUSPENSION AGITATION , 1997 .

[3]  E. L. Paul,et al.  Handbook of Industrial Mixing: Science and Practice , 2003 .

[4]  M. S. Greenwood,et al.  Measuring fluid and slurry density and solids concentration non-invasively. , 2004, Ultrasonics.

[5]  J. Coupland,et al.  Ultrasonic Attenuation Measurements of the Mixing, Agglomeration, and Sedimentation of Sucrose Crystals Suspended in Oil , 2011 .

[6]  Online measurement of particle size distribution during crystallization using ultrasonic spectroscopy , 2010 .

[7]  J. Tiihonen,et al.  Comparison of solids suspension criteria based on electrical impedance tomography and visual measurements , 2014 .

[8]  Gary B. Tatterson,et al.  Fluid mixing and gas dispersion in agitated tanks , 1991 .

[9]  David Julian McClements,et al.  Ultrasonic pulse echo reflectometer , 1991 .

[10]  Ryan Stevenson,et al.  Assessing solids concentration homogeneity in Rushton-agitated slurry reactors using electrical resistance tomography (ERT) , 2012 .

[11]  M. Kraume Mixing times in stirred suspensions , 1992 .

[12]  K. C. Lee,et al.  Particle concentration and mixing characteristics of moderate-to-dense solid-liquid suspensions , 2003 .

[13]  G. Meunier,et al.  TURBISCAN MA 2000: multiple light scattering measurement for concentrated emulsion and suspension instability analysis. , 1999, Talanta.

[14]  Peter Hauptmann,et al.  REVIEW ARTICLE: Application of ultrasonic sensors in the process industry , 2002 .

[15]  Carl Q. Howard,et al.  Determination of biomass concentration by measurement of ultrasonic attenuation , 2014 .

[16]  Ultrasonic velocimetry for the in situ characterisation of particulate settling and sedimentation , 2011 .

[17]  M. Mehrvar,et al.  Study of solid―liquid mixing in agitated tanks through electrical resistance tomography , 2010 .

[18]  A. W. Etchells,et al.  Suspension and Liquid Homogenization in High Solids Concentration Stirred Chemical Reactors , 1999 .

[19]  J. Ulrich,et al.  Ultrasonic crystallization monitoring technique for simultaneous in-line measurement of liquid and solid phase , 2013 .

[20]  Aniruddha B. Pandit,et al.  Review on Mixing Characteristics in Solid‐Liquid and Solid‐Liquid‐Gas Reactor Vessels , 2008 .

[21]  G. Micale,et al.  Assessment of Particle Suspension Conditions in Stirred Vessels by Means of Pressure Gauge Technique , 2002 .

[22]  Massimo Morbidelli,et al.  On multiple-particle effects in the acoustic characterization of colloidal dispersions , 1999 .

[23]  Jie Wu,et al.  Energy efficient high solids loading agitation for the mineral industry , 2010 .

[24]  RAPID COMMUNICATION: Ultrasonic measurements of suspended sediments: a concentration profiling system with attenuation compensation , 1996 .

[25]  Th.N. Zwietering Suspending of solid particles in liquid by agitators , 1958 .

[26]  J. Tsubaki,et al.  A new slurry evaluation technique by using ultrasonic attenuation , 2006 .

[27]  A. T. Mak,et al.  Solid-liquid mixing in mechanically agitated vessels , 1992 .

[28]  R. Visintainer,et al.  Development of A-scan ultrasound technique for measuring local particle concentration in slurry flows , 2012 .

[29]  G. Micale,et al.  Experiments and CFD predictions of solid particle distribution in a vessel agitated with four pitched blade turbines , 2001 .

[30]  Judith Ann Bamberger,et al.  Using ultrasonic attenuation to monitor slurry mixing in real time. , 2004, Ultrasonics.