This paper reports the results of an experimental study conducted to characterise the gas-liquid multiphase flows experienced within a vertical riser transporting a range of gas-liquid flow rates. The scale experiments were performed using an air/silicone oil mixture within a 6 m long riser. The superficial air velocities studied ranged from 0.047 to 2.836 m/ s, whilst maintaining a liquid supe...

Bubble column reactors are used in a wide variety of applications such as multiphase bioreactors, catalytic slurry reactors, and absorption processes. The superficial gas velocity-gas holdup relationship and transition point are two important parameters for characterizing the hydrodynamics of a bubble column reactor. In this study, systematic investigation of a nitrogen - water - glass bead...

The effective surface area ae of 14 variants of three highly effective types of packings (IMTP, Raschig Super-Ring (RSR) and Ralu-Flow) made of stainless steel or plastic is investigated as a function of the liquid superficial velocity. The packing size varied from 20 to 70 mm, and the liquid superficial velocity from 5 and 200 m/(mh). The comparison of the obtained data shows the following: Am...

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...

A 4-m high, 15.24-cm diameter semi-batch bubble column connected to one of three perforated plate gas distributors with open area ratios A = 0.57%, 0.99%, and 2.14% is employed to study gas holdup and flow regime in Rayon and Nylon fiber suspensions. This study determines the effect of superficial gas velocity, fiber type, fiber mass fraction, fiber length, and aeration plate open area ratio on...

In airlift reactors transport phenomena are achieved by pneumatic agitation and circulation occurs in a defined cyclic pattern through a loop. In the present work, the effect of geometrical relations on gas holdup and liquid velocity, and consequently on the gas-liquid mass transfer coefficient, was studied in a 6liter airlift bioreactor with AD/AR = 0.63; AD, downcomer cross-sectional area, an...

Experimental bubble size distributions and bubble mean diameters were obtained by means of a photographic technique for a direct-contact evaporator operating in the quasi-steady-state regime. Four gas superficial velocities and three different spargers were analysed for the air-water system. In order to assure the statistical significance of the determined size distributions, a minimum number o...

Drag reduction (DR) for air and water flowing in an inclined 0.0127 m diameter pipe was investigated experimentally. The fluids had an annular configuration and the pipe is inclined upward. The injection of drag reducing polymer (DRP) solution produced drag reductions as high as 71% with concentration of 100 ppm in the pipeline. A maximum drag reduction that is accompanied (in most cases) by a ...

The combined effect of superficial gas velocity, pH, initial phosphate concentration, and light intensity on cell growth was investigated for the mass production of cyanobacterial cells. The light intensity was manipulated to maintain a specific irradiation rate (q(i)) at a constant level for high cell density culture. The optimum condition for the batch culture was achieved at a superficial ga...