Analysis of particle cloud height dynamics in a stirred tank

AIChE Journal ◽  
2015 ◽  
Vol 62 (1) ◽  
pp. 338-348
Author(s):  
Matthias Eng ◽  
Rasmus Jonsson ◽  
Anders Rasmuson
Keyword(s):  
Stirred Tank ◽  
Particle Cloud ◽  
Cloud Height

scholarly journals CFD Modeling of Solid Suspension in a Stirred Tank: Effect of Drag Models and Turbulent Dispersion on Cloud Height

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Shitanshu Gohel ◽  
Shitalkumar Joshi ◽  
Mohammed Azhar ◽  
Marc Horner ◽  
Gustavo Padron
Keyword(s):  
Full Range ◽  
Operating Conditions ◽  
Solid Particles ◽  
Turbulent Dispersion ◽  
Stirred Tank ◽  
Cfd Modeling ◽  
Multiphase Model ◽  
Clear Liquid ◽  
Cloud Height ◽  
Drag Models

Many chemical engineering processes involve the suspension of solid particles in a liquid. In dense systems, agitation leads to the formation of a clear liquid layer above a solid cloud. Cloud height, defined as the location of the clear liquid interface, is a critical measure of process performance. In this study, solid-liquid mixing experiments were conducted and cloud height was measured as a function operating conditions and stirred tank configuration. Computational fluid dynamics simulations were then performed using an Eulerian-Granular multiphase model. The effects of hindered and unhindered drag models and turbulent dispersion force on cloud height were investigated. A comparison of the experimental and computational data showed excellent agreement over the full range of conditions tested.

Removal of lead by sulfate-reducing bacteria in anaerobic continuous stirred tank reactors

2016 ◽  
Vol 14 (3) ◽  
pp. 557-561
Author(s):  
Nguyễn Thị Yên ◽  
Kiều Thị Quỳnh Hoa
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Stirred Tank ◽  
Synthetic Wastewater ◽  
Terminal Electron Acceptor ◽  
Stirred Tank Reactors ◽  
Sulfate Reducing ◽  
Sulfide Production ◽  
Continuous Stirred Tank ◽  
Continuous Stirred Tank Reactors ◽  
Reducing Bacteria

Lead contaminated wastewater negatively impacts to living organisms as well as humans. In recent years, a highly promising biological process using the anaerobic production of sulfide ions by sulfate-reducing bacteria has presented itself as an alternative option for the removal of lead. This process is based on microbial utilization of electron donors, such as organic compounds (carbon sources), and sulfate as the terminal electron acceptor for sulfide production. The biogenic hydrogen sulfide reacts with dissolved heavy metals to form insoluble metal sulfide precipitates Removal of lead by an enriched consortium of sulfate-reducing bacteria (DM10) was evaluated sulfate reduction, sulfide production and lead precipitation. Four parallel anaerobic continuous stirred tank reactors (CSTR, V = 2L) (referred as R1 - R4) were fed with synthetic wastewater containing Pb2+ in the concentrations of 0, 100, 150 and 200 mg L-1 of lead and operated with a hydraulic retention time of 5 days for 40 days. The loading rates of each metal in R1- R4 were 0, 20, 30 and 40 mg L-1 d-1, respectively. The results showed that there was no inhibition of SRB growth and that lead removal efficiencies of 99-100% for Pb2+ were achieved in R2 (100 mg L-1) and R3 (150 mg L-1) throughout the experiment. For the highest lead concentration of  200 mg L-1, a decrease in efficiency of removal (from 100 to 96%) was observed at the end of the experiment. The obtained result of this study might help for a better control operation and performance improvements of reactors.

Particle cloud kinetics in microgravity

1987 ◽  
Author(s):  
A. BERLAD ◽  
N. JOSHI ◽  
H. ROSS ◽  
R. KLIMEK
Keyword(s):  
Particle Cloud

Transient response of the 1-st order dynamic system with fluctuating parameters

1979 ◽  
Vol 44 (7) ◽  
pp. 2184-2195
Author(s):  
Vladimír Herles ◽  
Jan Čermák ◽  
Antonín Havlíček
Keyword(s):  
Dynamic System ◽  
Dynamic Behavior ◽  
Transient Response ◽  
Flow Model ◽  
Stirred Tank ◽  
Order System ◽  
Random Parameters ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Theoretical Results

The paper deals with the analysis of the dynamic behavior of the 1st order system with two random parameters. The theoretical results have been compared with experiments on flow model of a stirred tank reactor.

Venturi tube and single pipe inlet as gas distributors in hydrogenation of rape seed oil

1987 ◽  
Vol 52 (12) ◽  
pp. 2876-2885
Author(s):  
Milan Rylek ◽  
Petr Svoboda ◽  
Jiří Souček
Keyword(s):  
Seed Oil ◽  
Venturi Tube ◽  
Stirred Tank ◽  
Hydrogenation Rate ◽  
Rape Seed ◽  
Tank Reactor ◽  
Scale Unit ◽  
Single Pipe ◽  
Pipe Inlet ◽  
Made In

The effect of hydrogenation conditions on rate of hydrogenation of rape seed oil was studied in a laboratory stirred tank reactor of 250 ml volume, with nickel on kieselguhr catalyst within the range of conditions (150 ⪬ t(°C) ⪬ 190), (0.1 ⪬ P(MPa) ⪬ 1.0), and (0.01 ⪬ cNi(%) ⪬ 0.37). On the basis of these results a comparison of the effect of a Venturi tube and single pipe gas inlet as gas distributors on hydrogenation rate was made in a bench scale unit of 5 l volume.

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