Enhanced mass transfer at the rotating cylinder electrode. I. Characterization of a smooth cylinder and roughness development in solutions of constant concentration

1984 ◽  
Vol 14 (5) ◽  
pp. 555-564 ◽  
Author(s):  
D. R. Gabe ◽  
F. C. Walsh
Keyword(s):  
Mass Transfer ◽  
Rotating Cylinder ◽  
Constant Concentration ◽  
Rotating Cylinder Electrode ◽  
Smooth Cylinder

scholarly journals The Effect of Surface Roughness on Diffusion and Chemical Reaction Controlled Limiting Currents on a Rotating Cylinder Electrode in Deaerated Solutions with and Without CO2

CORROSION ◽  
10.5006/2552 ◽  
2018 ◽  
Vol 74 (9) ◽  
pp. 971-983 ◽  
Author(s):  
M. Al-Khateeb ◽  
R. Barker ◽  
A. Neville ◽  
H.M. Thompson
Keyword(s):  
Mass Transfer ◽  
Surface Roughness ◽  
Sherwood Number ◽  
Schmidt Number ◽  
Rotating Cylinder ◽  
Operating Conditions ◽  
Limiting Current ◽  
Surface Roughening ◽  
Rotating Cylinder Electrode ◽  
Effect Of Surface

The influence of surface roughness on mass transfer on a rotating cylinder electrode apparatus is investigated experimentally for a roughness pattern consisting of grooves parallel to the direction of fluid flow. Mass transfer from four different samples, with roughness values of 0.5 μm, 6 μm, 20 μm, and 34 μm, is measured using the limiting current technique for a range of rotational speeds in NaCl solutions saturated with N2 at pH = 3 and 4. Comparison with available correlations for the Sherwood number in literature (which are independent of surface roughness and are either for specific or arbitrary roughness patterns) shows that H+ mass transfer only correlates well for particular levels of roughness and that their accuracy can be increased if a correlation is utilized which is a function of surface roughening. A new correlation for Sherwood number as a function of the Reynolds number, Schmidt number, and surface roughness is proposed which agrees well with the mass transfer observed from all of the rough surface cases considered for this particular roughness pattern. Complementary experiments in CO2 environments were used to assess the combined limiting current associated with H+ and H2CO3 reduction (with the latter occurring via the buffering effect and being associated with the slow CO2 hydration step). Although the increase in sample roughness clearly leads to an increase in the rate of H+ mass transfer, in the CO2 environments considered, surface roughness is found to have no significant influence on the limiting current contribution from H2CO3, which can therefore be determined from Vetter’s equation across this range of operating conditions.

Electrochemical characterization of an oil/water alternately wetted rotating cylinder electrode

CORROSION ◽  
10.5006/3638 ◽  
2020 ◽  
Author(s):  
Linxiao Zheng ◽  
Ziming Wang ◽  
Guang-Ling Song
Keyword(s):  
Rotating Cylinder ◽  
Water Interface ◽  
Current Waveform ◽  
Longitudinal Displacement ◽  
Flow Conditions ◽  
Rotating Cylinder Electrode ◽  
Electrochemical Current ◽  
Oil Water ◽  
Displacement Speed

To characterize the corrosion at oil/water interfaces, a vertically adjustable rotating cylinder electrode (VA-RCE) was developed based on the concept of “alternate wetting cell”, in which the electrochemical current reflecting the wet state of the RCE surface can be continuously monitored. Under a sinusoidal moving mode, the current waveform varied with the rotation rate and the longitudinal displacement speed or amplitude of the VA-RCE, implying that the dynamic wetting behavior of the VA-RCE surface in the oil/water interface region was influenced by the flow conditions; the replacement of oil phase by water phase became easier with increasing flow rate and alternating frequency of change between water wet and oil wet. The results also indicated that the wettability of the VA-RCE surface could be modified by the formation of corrosion products. All the results suggested that the VA-RCE could be used to quantitatively characterize the dynamic water/oil wetting state and the corrosion at an oil/water interface in a multiphase flow.

Patch and Whole of Surface Mass-Transfer Rate Measurements on a Stepped Rotating Cylinder Electrode

CORROSION ◽  
2005 ◽  
Vol 61 (10) ◽  
pp. 968-975 ◽  
Author(s):  
K. Bremhorst ◽  
G. Kear ◽  
A. J. Keating ◽  
S-H. Huang
Keyword(s):  
Mass Transfer ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Rotating Cylinder ◽  
Rotating Cylinder Electrode ◽  
Surface Mass ◽  
Surface Mass Transfer
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