An analysis of the effects of the turbulent shear stress on cell culture in a stirred tank microcarrier bioreactor system using a synergistic combination of computational fluid dynamic (CFD)-based simulations and experiments is presented. A 3D computational model of Corning’s benchscale spinner flask was built using a state-of-the-art computational fluid dynamics (CFD) software, Flow3D (www.flo...

A stable and predictable production system is described for pilot plant quantities (milligram) of human lymphoid interferon, using suspension culture of an African Burkitt's lymphoma derived cell line Namalva with induction by Newcastle disease virus, B-1 strain. Cell cultures were grown in impeller-driven 50-liter fermentors with dilution of the postinduction culture using serum-free medium. H...

An experiment in forced vibration was conducted to study the fluidinduced rotordynamic force on an impeller whirling along a trajectory eccentric to its undeflected position. The prescribed whi l trajectory of the rotor is a circular orbit of a b e d radius. The force measured is a combination of a steady radial force due to volute asymmetries and an unsteady force due to the eccentric motion o...

Fluid dynamics simulations were applied for evaluating the suspension of particles in stirred vessels. The spatial distribution of particles throughout the vessel was characterized by a single parameter, here called the suspension quality (σ). Based on simulation results, a semi-empirical correlation was developed that correlated the suspension quality with the vessel geometry and solid and flu...

In this work, the effects of the types of frother (MIBC, pine oil, and A65) and operational parameters (impeller speed and air flow rate) on the flotation of quartz coarse particles was investigated using nano bubbles (NBs). Quartz particles of the size of -425+106 mm and three types of frother were used for the flotation experiments. Also the impeller speed was 600 to 1300 rpm, and the air flo...

Due to growth of mechanisation and automation, today’s industrial systems are becoming more complex. A small breakdown of any non-redundant machine component affects the operation of the entire system. To increase the availability and reliability, automated health monitoring and self-diagnostic capability (SDC) becoming essential to many industrial machineries like pumps, motors, etc. Condition...

The effect of impeller type and shear rate on the evolution of floc size and structure during shear-induced flocculation of polystyrene particles with aluminum sulfate is investigated by image analysis. One radial flow (six-blade Rushton turbine) and two axial flow (three-blade fluid foil, four-blade 45° pitch) impeller configurations are examined. The steady state average floc size is show...

The paper presents experimental evidence for the potentials of CFD methodology in revealing external flow and inner flow shear deformation rates in stirred tanks. Two basic issues are considered: could CFD produce valid solutions for shear rates in mixing vessels, and could practical shear rate differences relevant to specific impeller designs be reproduced by CFD. In a first part, the shear ra...

Stirred tank reactors are one of the most commonly used equipments in industry for achieving mixing and reaction. Flow fields in a stirred reactor are obtained via computational fluid dynamics. In this work CFD is used for the simulation of a reactive flow process consisting of a second order reaction. The extent of reaction is found to depend on impeller speed and its position from the bottom ...

This study involves CFD simulation of blood flow through a non-pulsatile, axial pump consisting of a complex multisectioned impeller with rotating and stationary components, and a stationary housing. We use a particlebased method, Smoothed Particle Hydrodynamics (SPH), to investigate the effects of varying the impeller blade pitch angle and the gap size between the rotor and housing. Regions of...