Studies on transfer processes in mixing vessels: suspending of solid particles in liquid by modified Rushton turbine agitators

1996 ◽  
Vol 15 (4) ◽  
pp. 221-229 ◽  
Author(s):  
R. V. Roman ◽  
R. Z. Tudose
Keyword(s):  
Solid Particles ◽  
Rushton Turbine ◽  
Transfer Processes ◽  
Mixing Vessels

Thermohydrodynamic Analysis of Solid-Liquid Lubricated Journal Bearings

1988 ◽  
Vol 110 (2) ◽  
pp. 367-374 ◽  
Author(s):  
M. M. Khonsari ◽  
V. Esfahanian
Keyword(s):  
Journal Bearing ◽  
Journal Bearings ◽  
Solid Particles ◽  
Governing Equations ◽  
Transfer Processes ◽  
Flow And Heat Transfer ◽  
Experimental Findings ◽  
Solid Liquid ◽  
General Computer Program ◽  
Good Agreement

Thermohydrodynamic theory is extended to include the effect of solid particles in hydrodynamically lubricated journal bearings. Appropriate governing equations and boundary conditions are derived for the fluid flow and heat transfer processes taking place in a finite journal bearing. A general computer program is developed to numerically solve the governing equations. Results are provided for biphase lubricants containing oil with molybdenum disulfide and polytetrafluoroethylene particles. The computational results are in good agreement with experimental findings. The results indicate that the bearing temperature field is affected significantly by the presence of particles in oil. Moreover, it is found that inclusion of particles in the lubricant results in a higher coefficient of friction in the mid-range of the Sommerfeld number compared to that of the clean oil.

Suspension of solid particles in vessels agitated by Rushton turbine imperllers

2016 ◽  
Vol 109 ◽  
pp. 730-733 ◽  
Author(s):  
R.K. Grenville ◽  
J.J. Giacomelli ◽  
D.A.R. Brown
Keyword(s):  
Solid Particles ◽  
Rushton Turbine

scholarly journals SIMULATION OF HEAT AND MASS TRANSFER PROCESSES UNDER GRANULES CAPSULATION IN FLUIDIZED BED

2018 ◽  
Vol 61 (4-5) ◽  
pp. 98
Author(s):  
Andrey A. Lipin ◽  
Vladimir O. Nebukin ◽  
Aleksandr G. Lipin
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Fluidized Bed ◽  
Residence Time ◽  
Solid Particles ◽  
Process Time ◽  
Coating Film ◽  
Transfer Processes ◽  
Mass Transfer Processes ◽  
The Impact

The paper studies capsulation of solid particles in a spout fluidized bed. A capsulation is used to protect the particles surface from the negative impact of environmental factors as well as to regulate of active component release rate. In this work, the capsulation is carried out by spraying of polymers dispersions on fluidized bed particles by means of pneumatic nozzles. Drops of polymer dispersion having faced with the particles are spred on their surface, forming a liquid film. Solvent removing by drying causes solidification of the film. Existing calculation methods of capsulation in the apparatuses with fluidized bed have a significant disadvantage. They do not consider the impact of capsule formation on the heat and mass transfer process of the solvent removing from the coating film. Combined modeling these processes allows more accurately predicting the required residence time of the capsulated material in the apparatus. The mathematical model, which allows predicting the change in coverage degree, the moisture content, the temperature of the particles in process time as well as required residence time in the apparatus, was developed. The comparison of the calculated and experimental data shows their good agreement. Taking into account the changes in evaporation surface due to the increasing of particles coverage degree in the capsulation process allows to describe the evolution of the particles parameters more adequately and to select of the process rational parameters.Forcitation:Lipin A.A., Nebukin V.O., Lipin A.G. Simulation of heat and mass transfer processes under granules capsulation in fluidized ber. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 4-5. P. 98-104

scholarly journals Periodic Behaviour of Mean Velocity Fields in Rushton Turbine (RT) Driven Stirred Tank

2019 ◽  
Vol 4 (6) ◽  
pp. 1341-1351
Author(s):  
Devarajan Krishna Iyer ◽  
Ajey Kumar Patel
Keyword(s):  
Axial Direction ◽  
Velocity Fields ◽  
Stirred Tank ◽  
Cfd Model ◽  
Mean Velocity ◽  
Rushton Turbine ◽  
Transfer Processes ◽  
Mass Transfer Processes ◽  
Periodic Behaviour ◽  
Cylindrical Region

The present study predicts the periodic behavior of mean velocity fields from the properly verified and validated CFD model to determine the extent of vortex and turbulent activity in a baffled tank stirred by standard six bladed Rushton Turbine. This region includes most of the vortex and turbulent action that controls the mixing and mass transfer processes in the stirred tank. The complexity of periodicity of mean radial and tangential velocities in the radial direction and mean axial velocity in the axial direction is used to fix the proper radial as well as axial extents of the vortex generated by RT. The extent of flow periodicity in the present stirred tank configuration is confined within a cylindrical region around the impeller of radius 0.753 times the impeller diameter and a height of 0.323 times the impeller diameter above and below the impeller center plane.

scholarly journals Estimating Just Suspension Speed for Stirred Reactors Using Power Measurement

2019 ◽  
Vol 2 ◽  
pp. 1-5
Author(s):  
Raja Shazrin Shah Raja Ehsan Shah ◽  
Baharak Sajjadi ◽  
Abdul Aziz Abdul Raman ◽  
Tiam You See ◽  
Shaliza Ibrahim ◽  
...  
Keyword(s):  
Power Consumption ◽  
Solid Phase ◽  
Liquid System ◽  
Solid Particles ◽  
Power Measurement ◽  
Internal Diameter ◽  
Rushton Turbine ◽  
Suspend Solid ◽  
Experimental Values ◽  
Solid Liquid

A simplified mathematical model was developed to predict the just suspended speed, NJS in a solid-liquid system by analyzing the net impeller power consumption to suspend solid particles. A fully baffled tank with an internal diameter of 400mm equipped with a standard Rushton turbine with a diameter of D=T/3 (133mm) was used in this work. Glass beads were used as the solid phase and distilled water was used as the liquid phase. Solid loadings were varied within the range of 0-27 wt%. Power consumption was measured using the shaft torque method. The predicted NJS values were in a good approximation to the experimental values using the Zwietering’s criterion with a deviation of 2 – 10%. The deviation was lower for higher solid concentrations.

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