LOCAL VELOCITY PROFILES MEASURED BY PIV IN AN VESSEL AGITATED BY RUSHTON TURBINE

The hydrodynamics and flow field were measured in an agitated vessel using 2-D Time Resolved Particle Image Velocimetry (2-D TR PIV). The experiments were carried out in a fully baffled cylindrical flat bottom vessel 300 mm in inner diameter. The tank was agitated by a Rushton turbine 100 mm in diameter. The velocity fields were measured for three impeller rotation speeds 300 rpm, 450 rpm and 600 rpm and the corresponding Reynolds numbers in the range 50 000 < Re < 100 000, which means that the fully-developed turbulent flow was reached. In accordance with the theory of mixing, the dimensionless mean and fluctuation velocities in the measured directions were found to be constant and independent of the impeller rotational speed. The velocity profiles were averaged, and were expressed by Chebyshev polynomials of the 1st order. Although the experimentally investigated area was relatively far from the impeller, and it was located in upward flow to the impeller, no state of local isotropy was found. The ratio of the axial rms fluctuation velocity to the radial component was found to be in the range from 0.523 to 0.768. The axial turbulence intensity was found to be in the range from 0.293 to 0.667, which corresponds to a high turbulence intensity

LOCAL VELOCITY PROFILES MEASURED BY PIV IN AN VESSEL AGITATED BY RUSHTON TURBINE

The hydrodynamics and flow field were measured in an agitated vessel using 2-D Time Resolved Particle Image Velocimetry (2-D TR PIV). The experiments were carried out in a fully baffled cylindrical flat bottom vessel 300 mm in inner diameter. The tank was agitated by a Rushton turbine 100 mm in diameter. The velocity fields were measured for three impeller rotation speeds 300 rpm, 450 rpm and 600 rpm and the corresponding Reynolds numbers in the range 50 000 &lt; Re &lt; 100 000, which means that the fully-developed turbulent flow was reached. In accordance with the theory of mixing, the dimensionless mean and fluctuation velocities in the measured directions were found to be constant and independent of the impeller rotational speed. The velocity profiles were averaged, and were expressed by Chebyshev polynomials of the 1st order. Although the experimentally investigated area was relatively far from the impeller, and it was located in upward flow to the impeller, no state of local isotropy was found. The ratio of the axial rms fluctuation velocity to the radial component was found to be in the range from 0.523 to 0.768. The axial turbulence intensity was found to be in the range from 0.293 to 0.667, which corresponds to a high turbulence intensity

Automotive Catalyst Production – Challenges for Chemical Engineers

The goal of this paper is to explain the chemical engineering backgrounds for operations participating on catalyst production in the automotive industry. It is shown that chemical engineering knowledge can help to a better understanding and optimisation of the production process. Besides the contribution mentioned above this paper brings the description of the up to date and interesting technology developed and patented by the worldwide leader in the chemical engineering - BASF. The car catalyst production process consists of two steps. Firstly, the coating slurry is produced and secondly, it is applied to the substrate. This paper focuses on the slurry production especially with regard to its dispersion, mixing, particle size reduction, and the influence of parameters affecting this proces

Dispersion Kinetics Modelling

Stirred tanks for dispersion, the pre-dispersion of two immiscible liquids or particulate solidliquid suspension are extensively used in the chemical, food, pharmaceutical and metallurgical industries, for purposes such as suspension/emulsion polymerisation, heterogeneous/phase-transfer catalytic chemical reactions, paint production and hydrometallurgical solvent extraction. The aim of this paper is to propose the simple dispersion model enabling the prediction of particle size changes over time and taking into account the type of breakup mechanisms, the non-homogeneity of local turbulent energy dissipation rate in an agitated vessel and the effect of the number of times the liquid passes through the impeller and the impeller zone. The model was successfully tested on data published by Ditl et al. (1981)

Simulation of process lines in MICROSOFT EXCEL nitric acid production

In this contribution, it is explained in the detail how useful Microsoft EXCEL could be for thesimulation of process lines. The report contains a manual flowsheet as well as a tutorial case and the results of its application for Nitric acid production can be gained

Automotive Catalyst Production – Challenges for Chemical Engineers

The goal of this paper is to explain the chemical engineering backgrounds for operations participating on catalyst production in the automotive industry. It is shown that chemical engineering knowledge can help to a better understanding and optimisation of the production process. Besides the contribution mentioned above this paper brings the description of the up to date and interesting technology developed and patented by the worldwide leader in the chemical engineering - BASF. The car catalyst production process consists of two steps. Firstly, the coating slurry is produced and secondly, it is applied to the substrate. This paper focuses on the slurry production especially with regard to its dispersion, mixing, particle size reduction, and the influence of parameters affecting this proces

Dispersion Kinetics Modelling

Stirred tanks for dispersion, the pre-dispersion of two immiscible liquids or particulate solidliquid suspension are extensively used in the chemical, food, pharmaceutical and metallurgical industries, for purposes such as suspension/emulsion polymerisation, heterogeneous/phase-transfer catalytic chemical reactions, paint production and hydrometallurgical solvent extraction. The aim of this paper is to propose the simple dispersion model enabling the prediction of particle size changes over time and taking into account the type of breakup mechanisms, the non-homogeneity of local turbulent energy dissipation rate in an agitated vessel and the effect of the number of times the liquid passes through the impeller and the impeller zone. The model was successfully tested on data published by Ditl et al. (1981)

LOCAL VELOCITY PROFILES MEASURED BY PIV IN AN VESSEL AGITATED BY RUSHTON TURBINE

<p>The hydrodynamics and flow field were measured in an agitated vessel using 2-D Time Resolved Particle Image Velocimetry (2-D TR PIV). The experiments were carried out in a fully baffled cylindrical flat bottom vessel 300 mm in inner diameter. The tank was agitated by a Rushton turbine 100 mm in diameter. The velocity fields were measured for three impeller rotation speeds 300 rpm, 450 rpm and 600 rpm and the corresponding Reynolds numbers in the range 50 000 &lt; Re &lt; 100 000, which means that the fully-developed turbulent flow was reached. In accordance with the theory of mixing, the dimensionless mean and fluctuation velocities in the measured directions were found to be constant and independent of the impeller rotational speed. The velocity profiles were averaged, and were expressed by Chebyshev polynomials of the 1^st order. Although the experimentally investigated area was relatively far from the impeller, and it was located in upward flow to the impeller, no state of local isotropy was found. The ratio of the axial rms fluctuation velocity to the radial component was found to be in the range from 0.523 to 0.768. The axial turbulence intensity was found to be in the range from 0.293 to 0.667, which corresponds to a high turbulence intensity.</p