Effect of Sparger Geometry on Gas-Volume-Fraction in Vertical Bubble-Column Flows Measured by Gamma-Densitometry Tomography (GDT)
Year: 2000
Type: article
Abstract: Gamma-densitometry tomography (GDT) is applied to study the effect of sparger geometry on the axial development of gas-volume-fraction profiles in a vertical bubble-column flow.Tests are conducted in a cylindrical vessel with an inner diameter of 0.48 m and a height of 3 m using air for the gas phase and lightweight mineral oil (Drakeol 10) for the liquid phase.A cross sparger with interchangeable arms is used to inject gas into the column at a height of 0.33 to 0.36 diameters above the bottom of the column.The superficial gas velocity ranges from 5 to 30 cn-ds, and the absolute column pressure ranges from 103 to 517 kPa.Radial distributions of gas volume fraction at eight axial locations from five different sparger geometries are presented.The sparger parameters examined are total open area of the holes, number of holes, hole diameter, and hole orientation.The development length of the gas-volume-fraction profile is found to increase with gas flow rate and column pressure for all sparger geometries tested.A comparison of the results from the five spargers indicates changes in development length of less than one diameter as the number and size of sparger holes are varied.More significant changes in development length, by c as much as four diameters at the highest gas velocity and column pressure, are found when varying hole orientation alone.For all spargers tested, average values of gas volume fraction in the fully developed region of the column differ by less than &O.02for the same flow conditions.
Language: English
Topic: Fluid Dynamics and Mixing
Subfield: Fluid Flow and Transfer Processes
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2142777260