Conventional airlift contactor (UT-ALC) was modified to improve its performance. The modified system (CDT-ALC) was tested for gas hold-up characteristics. Hydrodynamic environment depends on gas hold-up. New system reported 50 % higher gas hold-up. Linear relation between superficial gas velocity and fractional gas hold-up were developed from experimental data for both the reactors.

A novel multiple-airlifting membrane bioreactor is built with four sintered stainless steel tubular filters as the risers and downcomers. This work investigates the hydrodynamics including gas holdup, liquid velocity, liquid circulation and mixing times by aerating different number of risers (one to three) at superficial gas velocities of 0.02–0.07m/s The mass transfer phenomena, including oxyg...

An external liquid circulation is introduced into a traditional internal loop reactor in order to improve liquid circulation and increase the interface between gas and liquid phases. The effects of superficial gas velocity and external liquid circulation velocity on local and overall gas holdups are explored experimentally and numerically in the loop section of a combined gas-liquid contactor, ...

In this paper computational analysis of pressure and velocity in coal combustion system using the fluent software is analysed. The combustion of coal is used in circulating fluidized bed combustion system. This work is concerned about gas–solid two-phase mixtures flowing upwards through the fast beds. The type of information resulting from various ways of analyzing the pressure variations and t...

An experimental investigation has been carried out to study the flow regimes and pressure gradients of air-oil-water three-phase flows in 2.25 ID horizontal pipe at different flow conditions. The effects of water cuts, liquid and gas velocities on flow patterns and pressure gradients have been studied. The experiments have been conducted at 20 °C using low viscosity Safrasol D80 oil, tap water ...

This paper is concerned with semi-batch foams generated by injecting gas bubbles in a vertical column containing a liquid phase at rest. Its aim is to better understand the physical mechanisms responsible for foam formation at the liquid free surface and to predict the superficial gas velocity for onset of foaming. The model for predicting the onset of foaming is derived from the one-dimensiona...

effect of temperature on hydrodynamics of bubbling gas-solid fluidized beds was investigated.  experiments were carried out in the range of 25-600 ºc and different superficial gas velocities in the range of 0.17-0.78 m/s with sand particles. time-position trajectory of particles was obtained by radioactive particle tracking technique. these data were used for determination of mean velocities of...

The present work focuses on the measurements of bubble properties in heterogeneous bubbly flows in a square bubble column. A four-point optical fibre probe was used for this purpose. The accuracy and intrusive effect of the optical probe was investigated first. The results show that the optical probe underestimates bubble properties, such as, bubble velocity, local void fraction. The presence o...

Effect of temperature on hydrodynamics of bubbling gas-solid fluidized beds was investigated.  Experiments were carried out in the range of 25-600 ºC and different superficial gas velocities in the range of 0.17-0.78 m/s with sand particles. Time-position trajectory of particles was obtained by radioactive particle tracking technique. These data were used for determination of mean velocitie...

Vibration signals were measured in a lab-scale fluidized bed to investigate the changes in particle sizes. Experiments were carried out in the bed with a different mass fraction of coarser particles at different superficial gas velocities, and probe heights. The S-statistic test evaluates the dimensionless squared distance between two attractors reconstructed from time series of vibration signa...