The Experts below are selected from a list of 11217 Experts worldwide ranked by ideXlab platform
Mauro Rovatti - One of the best experts on this subject based on the ideXlab platform.
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terminal Settling Velocity and bed expansion characteristics of biofilm coated particles
Biotechnology and Bioengineering, 1999Co-Authors: Cristiano Nicolella, Renzo Di Felice, Mark M C Van Loosdrecht, Mauro RovattiAbstract:Fluid dynamic behavior of biofilm-coated particles in ambient water has been investigated. New experimental results are presented and compared with published data. From experimental measurements of the single particle terminal Settling Velocity the corresponding drag coefficient was found to be larger (by a factor of 1.6) than that for a smooth, rigid sphere at the same Reynolds number. A new simple correlation describing this finding is suggested. For multiparticle systems the Richardson-Zaki equation, derived empirically for rigid particles, provided a satisfactory description of biological beds. Of the two numerical parameters characterizing the expansion law, i. e. the slope n and the extrapolation to voidage equal one ui, the first was found to be similar to that suggested by Richardson and Zaki (1954), whereas ui gave results smaller than the single-particle terminal Settling Velocity, in contrast with the mentioned work but in agreement with more recently published behavior.
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terminal Settling Velocity and bed expansion characteristics of biofilm coated particles
Biotechnology and Bioengineering, 1999Co-Authors: Cristiano Nicolella, Renzo Di Felice, Mark M C Van Loosdrecht, Mauro RovattiAbstract:Fluid dynamic behavior of biofilm-coated par- ticles in ambient water has been investigated. New ex- perimental results are presented and compared with published data. From experimental measurements of the single particle terminal Settling Velocity the correspond- ing drag coefficient was found to be larger (by a factor of 1.6) than that for a smooth, rigid sphere at the same Reynolds number. A new simple correlation describing this finding is suggested. For multiparticle systems the Richardson-Zaki equation, derived empirically for rigid particles, provided a satisfactory description of biological beds. Of the two numerical parameters characterizing the expansion law, i.e. the slope n and the extrapolation to voidage equal one ui, the first was found to be similar to that suggested by Richardson and Zaki (1954), whereas ui gave results smaller than the single-particle terminal Settling Velocity, in contrast with the mentioned work but in agreement with more recently published be- havior. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 62: 62-70, 1999.
Renzo Di Felice - One of the best experts on this subject based on the ideXlab platform.
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empirical relationships for the terminal Settling Velocity of spheres in cylindrical columns
Chemical Engineering & Technology, 1999Co-Authors: Ralf Kehlenbeck, Renzo Di FeliceAbstract:The terminal Settling Velocity of spherical particles was experimentally investigated in cylindrical columns in the range of Reynolds numbers 2≤Re t ∞≤185 and of particle-to-column diameter ratios, λ, about 0.1 to 0.9. It was observed that none of the existing equations relating the terminal Settling Velocity, u t , to the diameter ratio, λ, is fully satisfactory. For this reason two new empirical calculation methods are proposed which enable the determination of u t in the whole range of both Reynolds number, Re t ∞, and diameter ratio, λ.
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terminal Settling Velocity and bed expansion characteristics of biofilm coated particles
Biotechnology and Bioengineering, 1999Co-Authors: Cristiano Nicolella, Renzo Di Felice, Mark M C Van Loosdrecht, Mauro RovattiAbstract:Fluid dynamic behavior of biofilm-coated particles in ambient water has been investigated. New experimental results are presented and compared with published data. From experimental measurements of the single particle terminal Settling Velocity the corresponding drag coefficient was found to be larger (by a factor of 1.6) than that for a smooth, rigid sphere at the same Reynolds number. A new simple correlation describing this finding is suggested. For multiparticle systems the Richardson-Zaki equation, derived empirically for rigid particles, provided a satisfactory description of biological beds. Of the two numerical parameters characterizing the expansion law, i. e. the slope n and the extrapolation to voidage equal one ui, the first was found to be similar to that suggested by Richardson and Zaki (1954), whereas ui gave results smaller than the single-particle terminal Settling Velocity, in contrast with the mentioned work but in agreement with more recently published behavior.
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terminal Settling Velocity and bed expansion characteristics of biofilm coated particles
Biotechnology and Bioengineering, 1999Co-Authors: Cristiano Nicolella, Renzo Di Felice, Mark M C Van Loosdrecht, Mauro RovattiAbstract:Fluid dynamic behavior of biofilm-coated par- ticles in ambient water has been investigated. New ex- perimental results are presented and compared with published data. From experimental measurements of the single particle terminal Settling Velocity the correspond- ing drag coefficient was found to be larger (by a factor of 1.6) than that for a smooth, rigid sphere at the same Reynolds number. A new simple correlation describing this finding is suggested. For multiparticle systems the Richardson-Zaki equation, derived empirically for rigid particles, provided a satisfactory description of biological beds. Of the two numerical parameters characterizing the expansion law, i.e. the slope n and the extrapolation to voidage equal one ui, the first was found to be similar to that suggested by Richardson and Zaki (1954), whereas ui gave results smaller than the single-particle terminal Settling Velocity, in contrast with the mentioned work but in agreement with more recently published be- havior. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 62: 62-70, 1999.
Cristiano Nicolella - One of the best experts on this subject based on the ideXlab platform.
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terminal Settling Velocity and bed expansion characteristics of biofilm coated particles
Biotechnology and Bioengineering, 1999Co-Authors: Cristiano Nicolella, Renzo Di Felice, Mark M C Van Loosdrecht, Mauro RovattiAbstract:Fluid dynamic behavior of biofilm-coated particles in ambient water has been investigated. New experimental results are presented and compared with published data. From experimental measurements of the single particle terminal Settling Velocity the corresponding drag coefficient was found to be larger (by a factor of 1.6) than that for a smooth, rigid sphere at the same Reynolds number. A new simple correlation describing this finding is suggested. For multiparticle systems the Richardson-Zaki equation, derived empirically for rigid particles, provided a satisfactory description of biological beds. Of the two numerical parameters characterizing the expansion law, i. e. the slope n and the extrapolation to voidage equal one ui, the first was found to be similar to that suggested by Richardson and Zaki (1954), whereas ui gave results smaller than the single-particle terminal Settling Velocity, in contrast with the mentioned work but in agreement with more recently published behavior.
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terminal Settling Velocity and bed expansion characteristics of biofilm coated particles
Biotechnology and Bioengineering, 1999Co-Authors: Cristiano Nicolella, Renzo Di Felice, Mark M C Van Loosdrecht, Mauro RovattiAbstract:Fluid dynamic behavior of biofilm-coated par- ticles in ambient water has been investigated. New ex- perimental results are presented and compared with published data. From experimental measurements of the single particle terminal Settling Velocity the correspond- ing drag coefficient was found to be larger (by a factor of 1.6) than that for a smooth, rigid sphere at the same Reynolds number. A new simple correlation describing this finding is suggested. For multiparticle systems the Richardson-Zaki equation, derived empirically for rigid particles, provided a satisfactory description of biological beds. Of the two numerical parameters characterizing the expansion law, i.e. the slope n and the extrapolation to voidage equal one ui, the first was found to be similar to that suggested by Richardson and Zaki (1954), whereas ui gave results smaller than the single-particle terminal Settling Velocity, in contrast with the mentioned work but in agreement with more recently published be- havior. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 62: 62-70, 1999.
Ergun Kuru - One of the best experts on this subject based on the ideXlab platform.
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experimental investigation of the Settling Velocity of spherical particles in power law fluids using particle image shadowgraph technique
International Journal of Mineral Processing, 2016Co-Authors: Shivam Shahi, Ergun KuruAbstract:Abstract In this study, a new experimental technique, particle image shadowgraphy, is used to measure the Settling velocities of spherical particles (0.5 mm–2.0 mm) in Power-law fluids of variable viscosity and density. Different concentrations of CMC-water mixtures (0.14–0.28 wt%) are used as test fluids for the experiments. A new empirical equation, which is an improved version of the Shah et al. (2007) model, for predicting the Settling Velocity of a spherical particle in Power-law fluid is proposed. The new empirical model is found to give an average error of 10% in predicting the Settling Velocity.
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an experimental investigation of Settling Velocity of natural sands in water using particle image shadowgraph
Powder Technology, 2015Co-Authors: Shivam Shahi, Ergun KuruAbstract:Abstract Considering the extensive industrial usage of sands and the benefits of improving the effectiveness of such applications, a detailed experimental study on Settling of quartz sands in water is conducted. In this study, 980 quartz sand particles under four sieve sizes in the range of 0.35 mm–1.18 mm are used. Particle Image Shadowgraph (PIS), an accurate and efficient technique, is employed to determine the Settling Velocity of the particles. Using PIS in this novel application, the particle dimensions are characterized in terms of centricity, major/minor axes, and equivalent circular diameter. Using the shadowgraph results, an empirical model for Settling Velocity is developed based on a dimensionless diameter and Reynolds number. The dimensionless diameter is calculated from the equivalent circular diameter ( D c ) for the actual projected area of the particle. Furthermore, a simplistic empirical model based on equivalent circular radius ( R ce ) is proposed in which the particles are considered to be elliptical. Both models require only two-dimensional size parameters that can be easily measured. In this work, drag coefficient ( C d ) versus Reynolds number curve for sand particles in the intermediate regime is also presented. It is observed that C d attains an approximate value of 0.95 at Re p > 160. Also, for particles within a particular sieve diameter range, a large variance (16.35% to 92.35%) in Settling Velocity is observed. Based on the experimental measurement, a correlation between mean sieve diameter and equivalent circular diameter ( D c ) is developed which assists in more accurately predicting Settling Velocity. The new empirical models when compared with data in the literature predict the Settling Velocity with an average absolute error of 4.1% and 6.5%, respectively, for sieve sizes of 0.35 mm–1.18 mm.
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experimental investigation of Settling Velocity of natural sands in power law fluid using particle image shadowgraph
ASME 2015 34th International Conference on Ocean Offshore and Arctic Engineering, 2015Co-Authors: Shivam Shahi, Ergun KuruAbstract:In this study a new experimental technique, particle image shadowgraph (PIS), is used to investigate the Settling Velocity of natural sand particles in Power-law fluids. The particle Settling Velocity measurements are conducted within the Reynolds number of range of 0.01 to 17.00. Natural sands with mean sieve diameters in the range, 0.35 mm – 1.4 mm, are used. Six different equivalent diameter definitions are used to characterize size of the natural sand particles. Using the size and shape measurements in conjunction with PIS, correlations between the mean sieve diameter and equivalent diameters are obtained.Empirical correlations for predicting the Settling Velocity of sand particles in Power-law fluids are developed. Multiple linear regression analyses are performed with each fluid data and empirical coefficients for the models are also reported as functions of n and K. The models presented in the study give an average error of less than 20%. In addition, the multiple linear regression tools are applied to enhance the efficiency of the correlations by 3–5%. One of the major contributions of this study is that one can use any associated diameter to predict the Settling Velocity, which leads to greater flexibility.Copyright © 2015 by ASME
Joan Garcia - One of the best experts on this subject based on the ideXlab platform.
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Settling Velocity distribution of microalgal biomass from urban wastewater treatment high rate algal ponds
Algal Research-Biomass Biofuels and Bioproducts, 2016Co-Authors: Raquel Gutierrez, Enrica Uggetti, Ivet Ferrer, Carme Arnabat, Humbert Salvado, Joan GarciaAbstract:The aim of this study was to evaluate the Settling Velocity distribution of microalgal biomass with and without flocculant (Tanfloc SG). Microalgal biomass was obtained from two experimental wastewater treatment high rate algal ponds (HRAPs) operated with 4 and 8 days of hydraulic retention time. Two sets of dynamic sedimentation tests were carried out using a water elutriation apparatus. In the first set, most of the biomass of the 8 days-HRAP (63%) had Settling velocities between 16.5 and 4 m/h, while most of the biomass of the 4 days-HRAP (65%) had Settling velocities between 16.5 and 1 m/h. In the second set, most of the biomass from both HRAPs (60% from the 8 days-HRAP and 80% from the 4 days-HRAP) had Settling velocities between 6.5 and 0.4 m/h. In this second set, Settling velocities of 6.5 m/h, compared to 10% and 14% of microalgal biomass without flocculant for the 8 days-and 4 days-HRAPs, respectively. With flocculant, a very small amount of biomass (3% for the 4 days-HRAP and 8% for the 8 days-HRAP) had Settling velocities of 10(5) microalgae individuals/mL). According to our results, a settler designed with a critical Settling Velocity of 1m/h would reach biomass recoveries as high as 90-94% with flocculant compared to 77-88% without flocculant.
