Using electrical resistance tomography to characterize and optimize the mixing of micron sized polymeric particles in a slurry reactor

Latex Particles ◽

Liquid Mixing ◽

A solid-liquid mixing system has a significant role in the suspension polymerization, crystallization, adsorption, and solid-catalyzed reactions. In this study, Electrical Resistance Tomography (ERT) was employed to investigate the effect of the particle size, the design parameters such as impeller type, impeller clearance and impeller diameter as well as operating conditions such as impeller speed, impeller pumping mode, and solids concentration on the mixing of micron sized latex particles in a slurry reactor. The ERT data were used to calculate the concentration profile and the degree of homogeneity in three dimensions, as a function of design parameters and operating within the reactor. In this work, tap water and latex particles (5.2 µm, 8.5 µm, 9.1 µm) were used as liquid and solid phase, respectively. Six axial impellers were utilized (A310, A100, A200, A320, A315, 3AM) with impeller speed (N) varying from 252 rpm to 400 rpm. Impeller diameter to tank diameter ratios (D/T) were in the range of 0.29 to 0.47 while, the impeller clearance (C/T) was changed in the range of T/3.8 to T/2.5. Impeller pumping was tested in both downward and upward directions. The concentration of latex particles was ranged between 15 wt% and 30 wt%. This study shows that the level of homogeneity in a solid-liquid mixing system improved with the increase in impeller speed. However, after achieving the maximum level of homogeneity, any further rise in the impeller speed had a detrimental effect on the level of homogeneity. A310 impeller, wtih D/T ratio of 0.31, demonstrated the highest level of homogeneity while the upward pumping direction was found to be more efficient than the downward one. In addition, a clearance of T/3 proved to create the highest level of homogeneity. Also, the results showed that a rise in the size and concentration of particles decreases the level of homogeneity. Thus, 5.2 µm latex particles with the concentration of 15 wt% demonstrated the highest level of homogeneity. Applying the findings of this study will lead to improved equipment design, chemical cost reduction, increased production rate, improved quality of products, and more efficient use of power in slurry reactors.

Solid-liquid mixing studies in lab-scale flotation tank using electrical resistance tomography

Mining Metallurgy & Exploration ◽

10.1007/bf03402279 ◽

2014 ◽

Vol 31 (3) ◽

pp. 180-180

Author(s):

Lucas Pich Machado

Keyword(s):

Electrical Resistance ◽

Liquid Mixing ◽

Study of solid–liquid mixing in agitated tanks through electrical resistance tomography

Chemical Engineering Science ◽

10.1016/j.ces.2009.10.007 ◽

2010 ◽

Vol 65 (4) ◽

pp. 1374-1384 ◽

Cited By ~ 71

Author(s):

Seyed Hosseini ◽

Dineshkumar Patel ◽

Farhad Ein-Mozaffari ◽

Mehrab Mehrvar

Keyword(s):

Electrical Resistance ◽

Liquid Mixing ◽

A Novel Approach For Analyzing Mixing Quality In Solid-Liquid Stirred Tanks Via Coupled Computational Fluid Dynamics - Discrete Element Method And Electrical Resistance Tomography

10.32920/ryerson.14655444.v1 ◽

2021 ◽

Author(s):

Cindy Tran

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Discrete Element Method ◽

Electrical Resistance ◽

Particle Interaction ◽

Discrete Element ◽

Fluid Particle ◽

Mixing Quality ◽

The mixing quality of a solid-liquid stirred tank operating in the turbulent regime was investigated, numerically and to an extent experimentally. Simulations were performed by coupling Computational Fluid Dynamics (CFD) and the Discrete Element Method (DEM). The results were evaluated against experimental data obtained using Electrical Resistance Tomography (ERT). This facilitated a novel and more rigorous assessment of CFD-DEM coupling – i.e. based on the spatial distribution of particle concentrations. Furthermore, a new mixing index definition was developed to quantify suspension quality to work in tandem with existing dispersion mixing indexes. This provides a more complete interpretation of mixing quality. In this work, it was found that the model underestimated suspension and dispersion due to model limitations associated with mesh size and fluid-particle interaction models. Furthermore, the predicted mixing quality was sensitive to changes in the drag model, including other fluid-particle interaction forces in simulations, and variations in certain particle properties

A Novel Approach For Analyzing Mixing Quality In Solid-Liquid Stirred Tanks Via Coupled Computational Fluid Dynamics - Discrete Element Method And Electrical Resistance Tomography

10.32920/ryerson.14655444 ◽

2021 ◽

Author(s):

Cindy Tran

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Discrete Element Method ◽

Electrical Resistance ◽

Particle Interaction ◽

Discrete Element ◽

Fluid Particle ◽

Mixing Quality ◽

The mixing quality of a solid-liquid stirred tank operating in the turbulent regime was investigated, numerically and to an extent experimentally. Simulations were performed by coupling Computational Fluid Dynamics (CFD) and the Discrete Element Method (DEM). The results were evaluated against experimental data obtained using Electrical Resistance Tomography (ERT). This facilitated a novel and more rigorous assessment of CFD-DEM coupling – i.e. based on the spatial distribution of particle concentrations. Furthermore, a new mixing index definition was developed to quantify suspension quality to work in tandem with existing dispersion mixing indexes. This provides a more complete interpretation of mixing quality. In this work, it was found that the model underestimated suspension and dispersion due to model limitations associated with mesh size and fluid-particle interaction models. Furthermore, the predicted mixing quality was sensitive to changes in the drag model, including other fluid-particle interaction forces in simulations, and variations in certain particle properties

Analysis of immiscible liquid-liquid mixing in stirred tanks by Electrical Resistance Tomography

Chemical Engineering Science ◽

10.1016/j.ces.2020.115898 ◽

2020 ◽

Vol 227 ◽

pp. 115898 ◽

Cited By ~ 2

Author(s):

Francesco Maluta ◽

Giuseppina Montante ◽

Alessandro Paglianti

Keyword(s):

Electrical Resistance ◽

Immiscible Liquid ◽

Stirred Tanks ◽

Liquid Mixing

Quantitative Evaluations with 2D Electrical Resistance Tomography in the Low Conductivity Solutions Using 3D Printed Phantoms for Crystallization Process Monitoring

10.20944/preprints202012.0104.v1 ◽

2020 ◽

Author(s):

Guruprasad Rao ◽

Muhammad Awais Sattar ◽

Radosław Wajman ◽

Lidia Jackowska Strumiłło

Keyword(s):

Electrical Resistance ◽

Sucrose Solution ◽

Tap Water ◽

Imaging Modality ◽

Spatial Accuracy ◽

Reconstruction Algorithms ◽

Demineralized Water ◽

Industrial Grade ◽

Quantitative Evaluations

Crystallization is a significant procedure in the manufacturing of many pharmaceutical and solid food products. In-situ Electrical Resistance Tomography (ERT) is a novel Process Analytical Tool (PAT) to provide a cheap and quick way to test, visualize, and evaluate the progress of crystallization processes. In this work, the spatial accuracy of the non-conductive phantoms in low conductivity solutions was evaluated. Gauss-Newton, Linear Back Projection, and iterative Total Variation reconstruction algorithms were used to compare the phantom reconstructions for tap water, industrial-grade saturated sucrose solution, and demineralized water. Cylindrical phantom measuring 10 mm in diameter and a cross-section area of 1.5 % of the total beaker area was detected at the center of the beaker. Two phantoms with a 10 mm diameter were visualized separately in non-central locations. The quantitative evaluations were done for the phantoms with radii ranging from 10 mm to 50 mm in demineralized water. Multiple factors such as ERT device and sensor development, FEM mesh density and simulations, image reconstruction algorithms, number of iterations, segmentation methods, and morphological image processing methods were discussed and analyzed to achieve spatial accuracy. The development of ERT imaging modality for the purpose of monitoring crystallization in low conductivity solutions was performed satisfactorily.