the mixing behavior of the gas-liquid phase in three loop bioreactors was investigated. a gas-induced external airlift loop bioreactor (ealb), a forced-liquid vertical tubular loop bioreactor (vtlb) and a forced-liquid horizontal tubular loop bioreactor (htlb) were used for mixing studies as well as biomass production from natural gas. the effect of design parameters, riser to downcomer cross s...

numerous investigations have been devoted towards understanding the hydrodynamics of gas jets in fluidized beds. however, most of them address the problem from  macroscopic point of view, which does not reveal the true behavior in the jet region at the single particle level. the present work aims to understand the jet behavior from a more fundamental level, i.e. the individual particle level. a...

Multicapillary column (MCC) ion mobility spectrometers (IMS) are increasingly in demand for medical diagnosis, biological applications and process control. In a MCC-IMS, volatile compounds are differentiated by specific retention time and ion mobility when rapid preseparation techniques are applied, e.g. for the analysis of complex and humid samples. Therefore, high accuracy in the determinatio...

analysis of non-laminar flows in coarse alluvial beds has a wide range of applications in various civil engineering, oil and gas, and geology problems. darcy equation is not valid to analyze transient and turbulent flows, so non-linear equations should be applied. non-linear equations are classified into power and binomial equations. binomial equation is more accurate in a wide range of velocit...

this study is concerned with the prediction of particles’ velocity in a dilute turbulent gas-solidboundary layer flow using a fully eulerian two-fluid model. the closures required for equationsdescribing the particulate phase are derived from the kinetic theory of granular flows. gas phaseturbulence is modeled by one-equation model and solid phase turbulence by mlh theory. resultsof one-way and...

We study the fundamental problem of two gas species in two dimensional velocity space whose molecules collide as hard circles in the presence of a flat boundary and with dependence on only one space dimension. The case of three-dimensional velocity space is a trivial generalization. More specifically the linear problem arising when the second gas dominates as a flow with constant velocity (and ...

In process industries, the measurement of void fraction is considerably important for sustainable operations. The erroneous calculation of void fraction is inevitably be the cause of many industrial accidents such as loss of coolant accidents in reactor operations, sweet corrosions in sub-sea oil and gas pipelines and an in-efficient process control of chemical plants. Keeping in view the impor...

the local solid flow structure of gas-solid bubbling fluidized bed was investigated to identify and characterize the particle clusters. extensive mathematical calculations were carried out using the energy-minimization multi-scale (emms) approach for evaluating cluster properties including the velocity, the size and the void fraction of clusters in the dense phase of the bed. the results showed...