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Journal of Applied Electrochemistry

, Volume 24, Issue 7, pp 658–665 | Cite as

Local enhancement of liquid-to-wall mass transfer by a single gas bubble

  • A. Ben Youssef
  • U. Haebel
  • Ph. Javet
Papers

Abstract

Local liquid-to-wall mass transfer enhancement by a single bubble was studied. Both photographic and local current measurements were taken. The effects of the bubble form, wake and trajectory were analysed for vertical and down-facing inclined electrodes. For angles lower than 40°, bubbles rise over the surface with small hops of regular amplitude. High current increases were observed where the bubble hits the electrode. For higher angles, the bubble glides, producing high constant currents.

Keywords

Physical Chemistry Mass Transfer High Angle Current Measurement Current Increase 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

List of symbols

A

electrode surface area (cm2)

cb

concentration in bulk (mol cm−3)

D

diffusivity (cm2 s−1)

Deq

bubble equivalent diameter (cm)

Dtr

bubble transverse diameter (cm)

F

Faraday's constant (A s mol−1)

i

current density (A cm−2)

Ine

natural convection limiting current (A)

Īmax

current peaks averaged on the nine MEs (A)

k

mass transfer coefficient (cm s−1)

M

Morton number, gν4ρ−1σ−3

n

valence change in electrochemical reaction

Re

Reynolds number, ρVDeqμ−1

t

time (s)

V

bubble velocity (cm s−1)

Greek symbols

α

inclination angle (degree)

ϱ

liquid density (g cm−3)

μ

dynamic viscosity (g cm−1 s)

ν

kinematic viscosity (cm2 s−1)

σ

surface tension (g s−2)

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Copyright information

© Chapman & Hall 1994

Authors and Affiliations

  • A. Ben Youssef
    • 1
  • U. Haebel
    • 1
  • Ph. Javet
    • 1
  1. 1.Institute of Chemical EngineeringSwiss Federal Institute of TechnologyLausanneSwitzerland

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