Analysis of the Microscopic Flow Structure of a CFB Downer Reactor Using Solids Concentration Signals
Bibliographic record
Abstract
The microflow structure in a downer reactor was studied by measuring the solids concentration fluctuations at various elevations and radial positions, using an optical fiber probe, at a sampling rate of 970 Hz. The downer reactor (0.1 m i.d. and 10 m high) was operated at gas velocities ranging from 3.5 to 10.0 m/s and solids flux from 50 to 200 kg/m2s, with spent FCC catalyst of Sauter mean diameter of 67 mm and density of 1500 kg/m3. The analysis of solids concentration time series was performed using statistical, spectral and chaos techniques. Results from these analyses were compared and related to the operating conditions (gas velocity and solids circulation rate) as well as to the spatial locations (radial and axial positions) in the downer reactor. Different techniques of time series analysis gave similar results but with different sensitivity to changes in the dynamics. A combination of the three signal analysis techniques proved to be more useful in providing more insight understanding of the microflow structure.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".