scholarly journals Influence of Groove Structure Parameters Based on Optimal Mass Transfer Coefficient on Vaporization Characteristics and Sealing Performance of Liquid Film Mechanical Seals

2021 ◽  
Vol 11 (19) ◽  
pp. 8941
Author(s):  
Xiaodong Xu ◽  
Chenbo Ma ◽  
Yuyan Zhang ◽  
Jianjun Sun ◽  
Qiuping Yu
Keyword(s):  
Mass Transfer ◽  
Liquid Film ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Vapor Phase ◽  
Volume Fraction ◽  
Helix Angle ◽  
Groove Depth ◽  
Phase Volume ◽  
Phase Volume Fraction

In this study, a spiral groove liquid film vaporization model based on the viscosity–temperature equation, fluid internal friction, saturation temperature, and pressure relationship equation was established. Using a multiphase flow model based on the finite volume method, the influence of the change in the mass transfer coefficient on the vaporization of the liquid film was studied. Moreover, the influence law of structural parameter changes in liquid film vaporization characteristics and sealing performance was analyzed. The results indicate that, with an increase in the mass transfer coefficient, the average vapor phase volume fraction first increases and then gradually stabilizes. When calculating the average vapor phase volume fraction, it is necessary to consider the influence of the mass transfer coefficient, whereas its effect on the opening force and leakage can usually be neglected. Under the optimal mass transfer coefficient conditions, the average vapor phase volume fraction increases with an increase in the helix angle, groove-weir ratio, and groove depth. By comparison, with an increase in the groove-diameter ratio, the average vapor phase volume fraction first increases and then decreases. The opening force decreases with an increase in the helix angle, groove-to-weir ratio, and groove depth. On the other hand, it first decreases and then increases with an increase in the groove-diameter ratio. The leakage rate increases first and then stabilizes with an increase in the helix angle. Moreover, it increases continuously with an increase in the groove-diameter ratio, groove-weir ratio, and groove depth.

The liquid side mass transfer coefficient in a film of liquid trickling down an expanded metal sheet packing

1980 ◽  
Vol 45 (5) ◽  
pp. 1343-1345
Author(s):  
Jan Lacina ◽  
Václav Kolář
Keyword(s):  
Mass Transfer ◽  
Liquid Film ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Metal Sheet ◽  
Expanded Metal

The paper presents experimentally obtained values of the liquid side mass transfer coefficient in a liquid film trickling down an expanded metal sheet packing and their analysis based on the model of unsteady absorption.

Hydrodynamics and mass transfer in turbulent liquid film flow involving the inlet portion

1981 ◽  
Vol 46 (2) ◽  
pp. 467-477 ◽  
Author(s):  
L. P. Kholpanov ◽  
V. A. Malyusov ◽  
N. M. Zhavoronkov
Keyword(s):  
Mass Transfer ◽  
Liquid Film ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Film Flow ◽  
Experimental Results ◽  
Inlet Section ◽  
Liquid Film Flow

Relationship for mass transfer coefficient in turbulent liquid film flow involving the inlet section have been derived theoretically. It was found that previously published experimental results were well explained by this theory.

Improvement of oxygen transfer efficiency in aerated ponds using liquid-film-assisted approach

2007 ◽  
Vol 55 (11) ◽  
pp. 183-191 ◽  
Author(s):  
H. Zhu ◽  
T. Imai ◽  
K. Tani ◽  
M. Ukita ◽  
M. Sekine ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Liquid Film ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Oxygen Transfer ◽  
Structural Parameters ◽  
Volumetric Mass Transfer Coefficient ◽  
Aeration System ◽  
Film Forming ◽  
Oxygen Transfer Efficiency

In aerated ponds, oxygen is generally supplied through either diffused or mechanical aeration means. Surface transfer and bubble transfer both contribute significantly to oxygen transfer in a diffused aeration system. In the present study, a liquid-film-forming apparatus (LFFA) is successfully developed on a laboratory scale to improve considerably the surface transfer via the unique liquid film transfer technique. The experimental results show that the volumetric mass transfer coefficient for LFFA alone is found to be as much as 5.3 times higher than that for water surface and that the total volumetric mass transfer coefficient for the liquid film aeration system increases by 37% in comparison with a conventional aeration system. Additionally, by tuning finely the structural parameters of the LFFA, it can also lead to high dissolved oxygen (DO) water with the DO percent saturation greater than 90%. More importantly, this result is accomplished by simply offering a single-pass aeration at a depth as shallow as 26 cm. As a result, the objective of economical energy consumption in aerated ponds can be realized by lowering the aeration depth without sacrificing the aeration efficiency. It is noteworthy that the data presented in this study are acquired either numerically or experimentally.

scholarly journals Gas Holdup and Gas-Liquid Mass Transfer Investigations in an Oscillatory Flow in a Baffled Column

2008 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
Taslim Taslim ◽  
Mohd Sobri Takriff
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Power Density ◽  
Volume Fraction ◽  
Gas Holdup ◽  
Gas Velocity ◽  
Liquid Mass ◽  
Liquid Mass Transfer ◽  
Superficial Gas Velocity

Gas holdup and gas-liquid mass transfer were investigated in a vertical baffled column. Pure carbon dioxide (C02) was used as the dispersed phase and tap water was used as the continuous phase. Gas holdup and mass transfer rate of C02 were measured under semi-batch condition, while the liquid phase was measured in batch mode. Gas holdup was estimated as the volume fraction of the gas in the two-phase mixture in the column. Mass transfer was expressed in terms of the liquid-side volumetric mass transfer coefficient (kLa). The effects of oscillation frequency, oscillation amplitude and gas flow rate on gas holdup andmass transfer were also determined. The results showed that a significant increase in gas holdup and mass transfer could be achieved in an oscillatory baffled column compared to a bubble column. Gas holdup and mass transfer were correlated as a function of power density and superficial gas velocity. Keywords: gas holdup, mass transfer coefficient, power density, superficial gas velocity

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