Autori: Mugurel Catalin Munteanu, Faical Larachi

Editorial: Chemical Engineering Science, 2008.

Rezumat:

Strong inhomogeneous magnetic fields using NbTi superconducting solenoid magnet up to 9 Tesla were used to investigate trickle-bed reactor hydrodynamics in emulated Earth-bound artificial micro/macrogravity. This environment was able to modify the apparent gravity for both diamagnetic and paramagnetic materials by means of magnetization body force densities. Body force vectors can be co-linear or antiparallel to the cocurrent two-phase downflow in trickle beds depending on material magnetic susceptibilities, magnetic field gradient and direction of magnetic field. Trickle-to-pulse flow transition was experimentally studied in microgravity, macrogravity and beyond-levitation conditions for the air-water and the phenylacetylene-kerosene/hydrogen systems. Magnetic fields were found to displace the transition boundary from trickle to pulse flow which was rationalized as an equivalent artifical gravity effect by formally commuting magnetization forces into equivalent scaling factors for gravitational acceleration. A theoretical analysis, using a modified Grosser et al. (1988) “artificial gravity” transition model, was attempted and model predictions were found to follow qualitatively experimental findings.

Cuvinte cheie: Microgravity; flow pattern; trickle bed; pulse flow; pulse frequency