The minimum in-line coalescence height of bubbles in non-Newtonian fluid
•Coalescence of in-line bubbles in power law non-Newtonian fluid is investigated.•Effects of operation conditions on minimum coalescence height are studied.•A correlation of minimum in-line bubble coalescence height is proposed. The minimum in-line coalescence height of bubbles generated from a subm...
Gespeichert in:
Veröffentlicht in: | International journal of multiphase flow 2017-06, Vol.92, p.161-170 |
---|---|
Hauptverfasser: | , , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | •Coalescence of in-line bubbles in power law non-Newtonian fluid is investigated.•Effects of operation conditions on minimum coalescence height are studied.•A correlation of minimum in-line bubble coalescence height is proposed.
The minimum in-line coalescence height of bubbles generated from a submerged nozzle was investigated experimentally in shear thinning non-Newtonian fluid at lower Reynolds number (2∼60). Carboxymethyl cellulose sodium (CMC) aqueous solution and carbon dioxide were used as the liquid phase and the gas phase, respectively. The process of the formation, movement and in-line coalescence of bubbles was visualized and recorded by a high-speed digital camera. The influences of bubble size, bubble generation frequency and liquid property on the minimum in-line coalescence height of bubbles were investigated by changing nozzle diameter, gas flow rate and the mass concentration of CMC aqueous solutions. For a given liquid, the generating frequency and size of bubbles increased but the minimum coalescence height of in-line bubbles decreased when the nozzle diameter and gas flow rate were increased. When the nozzle diameter and gas flow rate were fixed, the shear-thinning effect of CMC aqueous solution became stronger with increasing CMC mass concentration, which led to the increase in both the terminal rise velocity and average acceleration of the trailing bubble, consequently, the minimum in-line coalescence height of bubbles decreased. An empirical correlation for estimating the minimum in-line bubble coalescence height was proposed, the calculating values accords well with experimental data with a mean relative deviation only 7.6%.
[Display omitted] |
---|---|
ISSN: | 0301-9322 1879-3533 |
DOI: | 10.1016/j.ijmultiphaseflow.2017.03.011 |