Optimal Geometric Parameters in Baffled Surface Aeration Systems

2009 ◽  
Vol 4 (3) ◽  
Author(s):  
Achanta Ramakrishna Rao ◽  
Ajey Kumar Patel ◽  
Bimlesh Kumar
Keyword(s):  
Oxygen Transfer ◽  
Scale Up ◽  
Major Effect ◽  
Geometric Parameters ◽  
Aeration Tank ◽  
System Efficiency ◽  
Surface Aeration ◽  
Numerical Studies ◽  
Geometric Conditions ◽  
Circular Surface

Surface aeration systems are the most energy extensive unit. It is essential that the design of aeration systems should be as near optimal as is possible. Here, geometry of the aeration tank imparts a major effect on the system efficiency. Therefore, it is essential to have the optimal geometric conditions for the aeration tank. Optimal geometric conditions are also needed to scale up the laboratory result to the field installation. In the present work, experimental and numerical studies have been carried out on the effect of geometric parameters on oxygen transfer and macromixing time scale in baffled circular surface aeration tank to ascertain the optimal geometric conditions. Optimal geometric conditions developed in the present work may be useful in the field installation of the present systems.

Scale Up Parameter for Surface Aeration Systems

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Achanta Ramakrishna Rao ◽  
Kumar Bimlesh
Keyword(s):  
Reynolds Number ◽  
Froude Number ◽  
Unit Volume ◽  
Scale Up ◽  
Scaling Up ◽  
Surface Aeration ◽  
Circular Surface

Based on the scale up parameter, X (theoretical power per unit volume = F4/3 R1/3, where F is the impeller Froude number and R is the impeller Reynolds number), it is presented that the said parameter is useful in scaling up the micromixing time in surface aeration systems. Scale up equations correlating X with micromixing time have been presented for the geometrically similar circular surface aeration systems.

Oxygen transfer in circular surface aeration tanks

2009 ◽  
Vol 30 (7) ◽  
pp. 747-753 ◽  
Author(s):  
Achanta Ramakrishna Rao ◽  
Ajey Kumar Patel ◽  
Bimlesh Kumar
Keyword(s):  
Oxygen Transfer ◽  
Surface Aeration ◽  
Circular Surface

Power Generation and Oxygen Transfer Analyses for Micro Hydro-Turbine Installed in Wastewater Treatment Aeration Tank

2021 ◽  
pp. 1-16
Author(s):  
Abdel Rahman Salem ◽  
Alaa Hasan ◽  
Ahmad Abdelhadi ◽  
Saif Al Hamad ◽  
Mohammad Qandil ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Oxygen Transfer ◽  
Power Loss ◽  
Wastewater Treatment Plants ◽  
Aeration Tank ◽  
Hydro Turbine ◽  
Oxygen Transfer Efficiency ◽  
Aeration Process ◽  
The U.S ◽  
Water Height

Abstract This study targets one of the major energy consumers in the U.S. It suggests a new mechanical system that can recover a portion of the energy in Wastewater Treatment Plants (WWTPs). The proposed system entails a hydro-turbine installed above the air diffuser in the aeration tank to extract the water-bubble current's kinetic energy and converts it to electricity. Observing the optimum location of the turbine required multiple experiments where turbine height varies between 35% and 95% (water height percentages above the diffuser), while varying the airflow between 1.42 L/s (3 CFM) and 2.12 L/s (4.5 CFM) with a 0.24 L/s (0.5 CFM) increment. Additionally, three water heights of 38.1 cm (15”), 53.4 cm (21”), and 68.6 cm (27”) were considered to study the influence of the water height. It was noticed that the presence of the system has an adverse effect on the Standard Oxygen Transfer Efficiency (SOTE). Therefore, a small dual-blade propeller was installed right above the diffuser to directly mix the water in the bottom of the tank with the incoming air to enhance the SOTE. The results showed that the maximum reclaimed power was obtained where the hydro-turbine is installed at 65% - 80% above the diffuser. A reduction of up to 7.32% in SOTE was observed when the setup was placed inside the tank compared to the tank alone. The addition of the dual-blade propeller showed an increase in SOTE of 7.27% with a power loss of 6.21%, ensuring the aeration process was at its standards.

scholarly journals Scale-up of dextransucrase production by Leuconostoc mesenteroides in fed batch fermentation

2003 ◽  
Vol 46 (3) ◽  
pp. 455-459 ◽  
Author(s):  
Georgina L. Michelena ◽  
Aidín Martínez ◽  
Antonio Bell ◽  
Emilia Carrera ◽  
Roxana Valencia
Keyword(s):  
Oxygen Transfer ◽  
Enzyme Production ◽  
Batch Fermentation ◽  
Leuconostoc Mesenteroides ◽  
Scale Up ◽  
Oxygen Transfer Rate ◽  
Maximum Growth ◽  
Aeration Rate ◽  
Fed Batch ◽  
Fed Batch Fermentation

Fed batch fermentation was carried out for the dextransucrase enzyme production from Leuconostoc mesenteroides and the production was scale-up using oxygen transfer criteriuom. It was found that in 5 L vessel fermentation capacity, the best agitation speed was 225 min-1 and aeration rate was 0.15 vvm, obtaining dextransucrase activity of 127 DSU/mL.. The maximum enzyme production velocity coincide with the maximum growth velocity between 6 and 7 h of fermentation, which confirmed that dextransucrase production was associated with microbial growth. High enzyme yields were achieved during scale up based on oxygen transfer rate.

scholarly journals Influence of multiple load indentation on the mechanical and material behaviour of steel cone-cylinder under axial compression

2021 ◽  
Author(s):  
Olawale Ifayefunmi ◽  
Sivakumar D. ◽  
Amir Hafiz Sazali
Keyword(s):  
Test Data ◽  
Good Accuracy ◽  
Cone Angle ◽  
Geometric Parameters ◽  
Collapse Load ◽  
Material Behaviour ◽  
Numerical Studies ◽  
Multiple Load ◽  
Welding Technique ◽  
Load Indentation

Abstract The first set of test data on axial collapse of cone-cylinder assembly having multiple load indentation (MLI) and its accompanying numerical studies is presented in this paper. Two perfect and two imperfect steel cone-cylinders were prepared in pairs. The cone-cylinder models have the following geometric parameters: cone radius of 40 mm, cylinder radius of 70 mm,wall thickness of 0.5 mm and cone angle of 16.7°. Cone and cylinder part were combined using Metal Inert Gas (MIG) welding technique. Results show that the repeatability of the experiment was good (3% for the perfect and 7% for the imperfect). Also, numerical prediction tends to reproduce the test data with good accuracy. The error between both approches ranges from 1% to -8%. Furthermore, the influence of geometric parameters are also significant in determining the collapse load of this type of structure. Finally, the worst multiple load indentation (WMLI) was explored for steel cone-cylinders assembly using different number of load indentations. Results indicate that as the number of indents increases, the sensitivity of the cone-cylinder models to imperfection also increases. However, at different imperfection amplitude, A, two regions were observed; (i) the region where cone-cylinder with N = 8 is more sensitive (A < 1.5), and (ii) the region where N = 4 produce the worst imperfection (1.5 < A ≤ 1.68).

scholarly journals Oscillation of water mass appearing in square and circular surface aeration tanks.

1982 ◽  
Vol 15 (5) ◽  
pp. 405-408
Author(s):  
HITOSHI TAKASE ◽  
HAJIME UNNO ◽  
TAKASHI AKEHATA
Keyword(s):  
Water Mass ◽  
Surface Aeration ◽  
Circular Surface

Scale-up from shake flasks to fermenters in batch and continuous mode withCorynebacterium glutamicum on lactic acid based on oxygen transfer and pH

2007 ◽  
Vol 98 (4) ◽  
pp. 800-811 ◽  
Author(s):  
Juri M. Seletzky ◽  
Ute Noak ◽  
Jens Fricke ◽  
Eike Welk ◽  
Werner Eberhard ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Oxygen Transfer ◽  
Scale Up ◽  
Continuous Mode ◽  
Shake Flasks
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