A study on the influence of the tube layout on sub-channel hydrodynamics in a bubble column with internals

Comparative Hydrodynamic Analysis of Narrow and Pilot‐Scale Bubble Columns with Internals

“…A bimodal bubble size distribution is obtained for the narrow column (solid line) as known for empty BCRs (not shown here, see , ) operated at churn‐turbulent flow conditions . Here, the column wall stabilizes larger bubbles in the region without internals.…”

“…Reconstruction algorithms, e.g., filtered back projection, to obtain images with a spatial resolution of roughly 0.5 · 10 −3 m and post‐processing steps, e.g., normalizing, referencing, and thresholding, are required to extract hydrodynamic parameters. Details about the imaging technique and the post‐processing can be found elsewhere , , . The measurement height was adjusted to H c / D = 5 for both columns, which corresponds to 0.5 and 2 m above the sparger for the DN100 and DN400 column, respectively, which is located at well‐developed flow conditions.…”

“…5 % and below has hardly any effect , values larger than 20 % have a significant influence on the hydrodynamics. Compared to empty columns, the average gas holdup in columns with internals is increasing due to smaller and slower rising bubbles as a result of the prevailing breakup bubble formation mechanism , , . Tracer experiments have shown that internals also favor larger liquid circulation cells and suppress radial spreading and dispersion .…”

“…Tracer experiments have shown that internals also favor larger liquid circulation cells and suppress radial spreading and dispersion . Recent studies in a narrow column revealed that internals favor asymmetric flow patterns , while comparable analyses at pilot‐scale are not yet available.…”

Characterizing regime transitions in a bubble column with internals

“…In practice, dense heat‐exchanging tube bundles are usually installed to maintain ideal temperature in reactors. In the past two decades, more and more attentions have been focused on the effects of internals on the BC hydrodynamics 20‐26 . Chen et al 20 employed computed tomography (CT) and radioactive particle tracking (RPT) to measure the cross‐sectional gas holdup and liquid turbulence parameters, respectively.…”