Abstract
Axial flow behaviors are investigated with an optical fiber probe using FCC particles at extremely high solids circulation rates up to 700kg/m2s and superficial gas velocity ranging from 3-7m/s in a laboratory-scale downer system. Results show that axial distributions of particle velocity and solids holdup are significantly affected by the operating conditions. Superficial gas velocity is the predominance for particle velocity distribution while solids circulation rate plays a key role in solids holdup distribution. Development of solids flow can be accelerated by increasing superficial gas velocity and/or decreasing solids circulation rate. High solids holdup, higher than 0.06, can be achieved in the entire downer with relatively uniform axial profiles at solids circulation rate of 700kg/m2s indicating a preferential flow with reduced backmixing in the downer.
| Original language | English |
|---|---|
| Pages (from-to) | 153-164 |
| Number of pages | 12 |
| Journal | Powder Technology |
| Volume | 272 |
| DOIs | |
| Publication status | Published - 1 Mar 2015 |
| Externally published | Yes |
Keywords
- Circulating fluidized bed downer
- Flow development
- High density
- Hydrodynamics
- Particle velocity
- Solids holdup
ASJC Scopus subject areas
- General Chemical Engineering