scholarly journals Turbulence in continuous flow surface aeration systems

2016 ◽  
Vol 75 (5) ◽  
pp. 1148-1157 ◽  
Author(s):  
Anurag Sharma ◽  
Thiyam Tamphasana Devi ◽  
Bimlesh Kumar
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Continuous Flow ◽  
Experimental System ◽  
Mass Transfer Process ◽  
Distribution Functions ◽  
Surface Aeration ◽  
Flow Surface ◽  
Continuous Surface

Turbulence characteristics in an optimal continuous surface aeration system were investigated in this study. The experimental system consists of a rectangular tank, where flow is driven by equally spaced aerators placed on the liquid surface. The mass-transfer coefficient and turbulent parameters at the tank's inlet and outlet were measured to enable analysis of their interdependent relationships. The turbulence parameters are linked closely to the system's mass-transfer process. Turbulent bursting analysis has shown that ejection and sweep events govern the hydrodynamics of the systems. Turbulent intensity increases with increasing speed of rotation, and consequently the mass-transfer coefficient also increases. The universal probability distribution functions of the velocity fluctuations in continuous flow surface aeration systems follow the Gram-Charlier series, based on exponential distribution, and the theoretical and experimental curves match.

scholarly journals Demonstration of Mass Transfer Using Aeration of Water

1970 ◽  
pp. 56-60
Author(s):  
Sultana R Syeda ◽  
BMS Arifin ◽  
Md M Islam ◽  
Anup Kumar
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Dimensional Analysis ◽  
Engineering Students ◽  
Chemical Engineering ◽  
Bubble Column ◽  
Mass Transfer Process ◽  
Design Parameters ◽  
Sieve Tray

An experiment was developed using aeration of water for demonstrating the phenomenon of mass transfer. The demonstration was designed to provide both conceptual and practical insight of the mass transfer process. A bubble column fitted with a sieve tray was used to carry out the experiment. The air flow rate and hole size of the sieve tray were varied. Mass transfer coefficient was obtained from the initial and final oxygen concentrations of the aerated water. A dimensionless correlation for mass transfer coefficient in terms of the experimental variables was developed by dimensional analysis and regression of the experimental data. The demonstration is suitable for chemical and other engineering students and can be fit in one laboratory session of three hours. The experimental setup is simple and inexpensive, and can be developed in-house. In addition to the laboratory demonstration, the experiment can also be used for optimizing design parameters of industrial aeration tanks. Keywords mass transfer coefficient; aeration; bubble column; dimensional analysis; Stanton number. DOI: 10.3329/jce.v25i0.7239Journal of Chemical Engineering, IEB Vol. ChE. 25, No. 1, December 2010 pp.56-60

Absorption of oxygen into solutions of polymers

1986 ◽  
Vol 51 (10) ◽  
pp. 2127-2134 ◽  
Author(s):  
František Potůček ◽  
Jiří Stejskal
Keyword(s):  
Mass Transfer ◽  
Aqueous Solutions ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Liquid Flow ◽  
Flow Curve ◽  
Liquid Flow Rate ◽  
Polymer Concentration ◽  
Newtonian Liquids

Absorption of oxygen into water and aqueous solutions of poly(acrylamides) was studied in an absorber with a wetted sphere. The effects of changes in the liquid flow rate and the polymer concentration on the liquid side mass transfer coefficient were examined. The results are expressed by correlations between dimensionless criteria modified for non-Newtonian liquids whose flow curve can be described by the Ostwald-de Waele model.

scholarly journals Development of mass and heat transfer coupled model of hollow fiber membrane for salt recovery from brine via osmotic membrane distillation

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Sher Ahmad ◽  
Gabriela Vollet Marson ◽  
Waheed Ur Rehman ◽  
Mohammad Younas ◽  
Sarah Farrukh ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Heat And Mass Transfer ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Membrane Distillation ◽  
Fiber Membrane ◽  
Salt Recovery ◽  
Osmotic Solution

Abstract Background In this research work, a coupled heat and mass transfer model was developed for salt recovery from concentrated brine water through an osmotic membrane distillation (OMD) process in a hollow fiber membrane contactor (HFMC).The model was built based on the resistance-in-series concept for water transport across the hydrophobic membrane. The model was adopted to incorporate the effects of polarization layers such as temperature and concentration polarization, as well as viscosity changes during concentration. Results The modeling equations were numerically simulated in MATLAB® and were successfully validated with experimental data from literature with a deviation within the range of 1–5%. The model was then applied to study the effects of key process parameters like feed concentrations, osmotic solution concentration, feed, and osmotic solution flow rates and feed temperature on the overall heat and mass transfer coefficient as well as on water transport flux to improve the process efficiency. The mass balance modeling was applied to calculate the membrane area based on the simulated mass transfer coefficient. Finally, a scale-up for the MD process for salt recovery on an industrial scale was proposed. Conclusions This study highlights the effect of key parameters for salt recovery from wastewater using the membrane distillation process. Further, the applicability of the OMD process for salt recovery on large scale was investigated. Sensitivity analysis was performed to identify the key parameters. From the results of this study, it is concluded that the OMD process can be promising in salt recovery from wastewater.

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