Investigation of Local Mass Transfer in a Packed Bed of Pall Rings Using a Limiting Current Technique
Bibliographic record
Abstract
The mass-transfer coefficients at varied axial, radial, and angular positions in a packed bed of Pall rings were measured using the limiting current technique. The experimentation was carried out in a 0.30-m-diameter column with a bed height of 5.5 column diameters. Ferri-/ferrocyanide ions were used as the redox couple for the mass-transfer measurement. The local mass-transfer rate was found to be strongly dependent on the liquid feed distribution, especially at the top section of the packed bed. The local mass-transfer rate also varied significantly in the axial and radial directions in the packed bed. A maximum mass-transfer rate was observed at an axial distance of 1.5 column diameters ( x / D = 1.5) when the multipoint liquid distributor was used while the highest transfer rate occurred at x / D = 2.5 for the single-point liquid distributor. However, for both types of liquid distributors the mass-transfer rate became steady at x / D > 4.5. The wall flow also reached steady-state x / D = 3.5. The average mass-transfer rate with the multipoint distributor was about 14% higher than that with the single-point distributor.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".