On Stability of a Bubble Column

0388399 - ÚCHP 2014 RIV GB eng J - Journal Article
Růžička, Marek
On Stability of a Bubble Column.
Chemical Engineering Research and Design. Roč. 91, č. 2 (2013), s. 191-203. ISSN 0263-8762. E-ISSN 1744-3563
R&D Projects: GA ČR GA104/07/1110
Institutional support: RVO:67985858
Keywords : bubble column * flow regimes * steady solution
Subject RIV: CI - Industrial Chemistry, Chemical Engineering
Impact factor: 2.281, year: 2013

The governing equations based on the mass balance of the gas phase in the bubble column were formulated, together with the closures for the two typical operational regimes, homogeneous and heterogeneous. The equations were analysed for the steady state solutions and their stability. Two solutions were found for the uniform regime, one stable and one unstable. Only one stable solution was found for the nonuniform regime. These solutions were investigated as they depend on the control parameters, namely on the gas input, terminal bubble speed, and the form of the closure relations for the collective bubble speed. The two branches of the uniform solution merge in the turning point bifurcation, at large enough gas input. The nonuniform solution branch persists for all plausible parameter values. Besides these physically relevant solutions, one solution branch was identified as physically unacceptable. The physical reasons for the system stability were discussed. The linear approximation of the bubble column dynamics was performed and the relaxation time was estimated. The full nonlinear dynamics was considered too. Both the steady and unsteady behaviour of the bubble column was compared with experimental data.
Permanent Link: http://hdl.handle.net/11104/0220428