Bubble size and bubble velocity distribution in bubble columns under industrial conditions

Abstract

Bubble column reactors are widely used in many industrial applications due to their simplicity and safety of operation. Despite these advantages, the design and scale‐up of bubble column reactors is still challenging especially for industrial conditions at elevated pressure and temperature. One reason is the uncertainties concerning the specific interfacial area which is directly dependent on the bubble size distribution, bubble velocity, and gas hold‐up. All these parameters are difficult to measure under industrial conditions due to the opaqueness of the bubbly flow and the safety risks of using organic solvents at elevated pressures and temperatures. This article introduces endoscopic bubble image velocimetry, a new measuring method that enables the detection of bubble sizes and bubble velocities in organic solvents at elevated pressure and temperature (pmax = 1.85 MPa and Tmax = 70 °C) for maximal gas hold‐ups of 16 %. For this system it becomes evident that the bubble size distribution for low superficial gas velocities is almost unaffected by pressure and temperature, whereas the bubble velocity decreases slightly.

High‐Throughput Object Recognition and Sizing in Disperse Systems

“…Further analysis of size and shape requires fast and reliable detection of high quantities of particles on the images. Endoscopy combined with automated image analysis is well‐established for emulsions or bubbles produced in stirred vessels, the dispersed volume fraction in these studies, however, was below 45 % .…”

Auslegung von Blasensäulen mithilfe von Compartmentmodellen

“…Messprinzipien für die experimentelle Ermittlung der benötigten Gasphasenparameter sind unter anderem in und zusammengefasst. Es kann jedoch auch auf eine Vielzahl an Korrelationen aus der Literatur , , , für die Festlegung des Gasgehalts oder der Blasengröße zurückgegriffen werden. …”

Experimental methods in chemical engineering: Fluorescence emission spectroscopy

“…Eng. published in 2016 and 2017 measured bubble size and velocity with endoscopic bubble image velocimetry (EBIV), where a laser excites a fluorescent dye in the liquid (blue cluster); evaluated diffusion rates of fluorescent molecules with confocal time‐lapse microscopy; verified how well fluorophores were grafted in compounds (green cluster); how well fluorescent molecule were functionalized by fluorescence spectroscopy (green cluster); monitored wastewater, by tracking cellular material and microbiological activity (blue cluster); and created a sensor for volatile organic compounds based on aggregation‐induced emission (AIE) from two‐dimensional MOFs (blue and green cluster) . Atomic fluorescence spectrometry (AFS) is an element specific technique that emits photons at the same wavelengths as the incident photons (green cluster) .…”