Scale-Up Effect of Riser Reactors (1): Axial and Radial Solids Concentration Distribution and Flow Development
Bibliographic record
Abstract
The influence of the riser diameter on the axial and radial solids holdup profiles and flow development is studied by measuring local solids holdups with a fiber-optic probe in a 10-m twin-riser system with 0.076- and 0.203-m inner diameters, at solids circulation rates of up to 200 kg/(m 2 s) and superficial gas velocities of up to 8 m/s. It was found that the solids concentration increases with increasing riser diameter. Furthermore, the radial profiles of the solids concentration are steeper with larger-diameter risers. For both risers, the flow development in the riser center is nearly instantaneous, with the solids concentration remaining low under all operating conditions. In the wall region, the flow development slows down. Moreover, the flow development is slower in the larger-diameter riser. Increasing the solids flux also slows the flow development. However, increasing the superficial gas velocity makes the flow development faster while also lengthening the fully developed region.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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 source (direct Gemma or distilled Codex), 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".