Oxygen transfer measurements during yeast fermentations in a pilot scale airlift fermenter

1995 ◽  
Vol 12 (1) ◽  
pp. 71
Author(s):  
A. B. Russell ◽  
C. R. Thomas ◽  
M. D. Lilly
Keyword(s):  
Oxygen Transfer ◽  
Pilot Scale ◽  
Airlift Fermenter

Oxygen transfer measurements during yeast fermentations in a pilot scale airlift fermenter

1995 ◽  
Vol 12 (1-2) ◽  
pp. 71-79 ◽  
Author(s):  
A. B. Russell ◽  
C. R. Thomas ◽  
M. D. Lilly
Keyword(s):  
Oxygen Transfer ◽  
Pilot Scale ◽  
Airlift Fermenter

Effect of orifice diameter, depth of air injection, and air flow rate on oxygen transfer in a pilot-scale, full lift, hypolimnetic aeratorA paper submitted to the Journal of Environmental Engineering and Science.

2009 ◽  
Vol 36 (1) ◽  
pp. 137-147 ◽  
Author(s):  
K.I. Ashley ◽  
D.S. Mavinic ◽  
K.J. Hall
Keyword(s):  
Flow Rate ◽  
Oxygen Transfer ◽  
Gas Flow ◽  
Pore Diameter ◽  
Oxygen Transfer Rate ◽  
Pilot Scale ◽  
Orifice Diameter ◽  
Transfer Rates ◽  
Oxygen Transfer Efficiency ◽  
Design Factors

A pilot-scale, full lift, hypolimnetic aerator was used to examine the effect of diffuser pore diameter, depth of diffuser submergence, and gas flow rate on oxygen transfer, using four standard units of measure for quantifying oxygen transfer: (a) KLa20 (h–1), the oxygen transfer coefficient at 20 °C; (b) SOTR (g O2·h–1), the standard oxygen transfer rate; (c) SAE (g O2·kWh–1), the standard aeration efficiency and (d) SOTE (%), the standard oxygen transfer efficiency. Diffuser depth (1.5 and 2.9 m) exerted a significant effect on KLa20, SOTR, SAE, and SOTE, with all units of measure increasing in response to increased diffuser depth. Both KLa20 and SOTR responded positively to increased gas flow rates (10, 20, 30, and 40 L·min–1), whereas both SAE and SOTE responded negatively. Orifice diameter (140, 400, and 800 µm) exerted a significant effect on KLa20, SOTR, SAE, and SOTE, with all units of measure increasing with decreasing orifice size. These experiments demonstrate how competing design factors interact to determine overall oxygen transfer rates in full lift hypolimnetic aeration systems. The practical application for full lift hypolimnetic aerator design is to maximize the surface area of the bubbles, use fine (i.e., ~140 μm) pore diameter diffusers, and locate the diffusers at the maximum practical depth.

scholarly journals Improving aeration systems in saline water (part II): effect of different salts and diffuser type on oxygen transfer of fine-bubble aeration systems

2021 ◽  
Author(s):  
J. Behnisch ◽  
M. Schwarz ◽  
J. Trippel ◽  
M. Engelhart ◽  
M. Wagner
Keyword(s):  
Oxygen Transfer ◽  
Large Scale ◽  
Saline Water ◽  
Tap Water ◽  
Pilot Scale ◽  
Mixed Salt ◽  
Water Oxygen ◽  
Aeration System ◽  
Fine Bubble ◽  
Scale Test

Abstract The objective of the present study is to investigate the different effects on the oxygen transfer of fine-bubble aeration systems in saline water. Compared to tap water, oxygen transfer increases due to the inhibition of bubble coalescence. In Part I of the present study, we investigated in lab-scale experiments the effect of design of diffuser membrane. The objective of Part II is the assessment of effects of different salts, diffuser type and diffuser density. We measured the concentration of various salts (MgCl2; CaCl2; Na2SO4; NaCl; KCl) above which coalescence is fully inhibited and oxygen transfer reaches its maximum (referred to as the critical coalescence concentration; CCC). For this purpose, we developed a new analytical approach, which enables to investigate the coalescence behaviour of any aeration system and (mixed) salt solution quickly and easily by evaluating the results of oxygen transfer tests. To investigate the transferability to large scale and the effect of diffuser type and density, we repeated lab-scale experiments in a 17,100 L pilot scale test tank and carried out additional tests with tube and plate diffusers at different diffuser densities. The results show, that despite the higher pressure drop, diffusers with dense slit density and smaller slits are to be recommended in order to improve efficiency of aeration systems in saline water.

Oxygen transfer in pilot-scale contactors: An experimental and computational investigation into the effect of contactor design

2018 ◽  
Vol 344 ◽  
pp. 173-183 ◽  
Author(s):  
Dale D. McClure ◽  
Zihe Liu ◽  
Geoffrey W. Barton ◽  
David F. Fletcher ◽  
John M. Kavanagh
Keyword(s):  
Oxygen Transfer ◽  
Pilot Scale ◽  
Computational Investigation

A calibration protocol of a one-dimensional moving bed bioreactor (MBBR) dynamic model for nitrogen removal

2012 ◽  
Vol 65 (7) ◽  
pp. 1172-1178 ◽  
Author(s):  
U. Barry ◽  
J.-M. Choubert ◽  
J.-P. Canler ◽  
A. Héduit ◽  
L. Robin ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Oxygen Transfer ◽  
Oxygen Transfer Rate ◽  
Pilot Scale ◽  
One Dimensional ◽  
Biofilm Thickness ◽  
Calibration Protocol ◽  
In Series ◽  
Nitrogen Treatment ◽  
Sensitive Parameters

This work suggests a procedure to correctly calibrate the parameters of a one-dimensional MBBR dynamic model in nitrification treatment. The study deals with the MBBR configuration with two reactors in series, one for carbon treatment and the other for nitrogen treatment. Because of the influence of the first reactor on the second one, the approach needs a specific calibration strategy. Firstly, a comparison between measured values and simulated ones obtained with default parameters has been carried out. Simulated values of filtered COD, NH4-N and dissolved oxygen are underestimated and nitrates are overestimated compared with observed data. Thus, nitrifying rate and oxygen transfer into the biofilm are overvalued. Secondly, a sensitivity analysis was carried out for parameters and for COD fractionation. It revealed three classes of sensitive parameters: physical, diffusional and kinetic. Then a calibration protocol of the MBBR dynamic model was proposed. It was successfully tested on data recorded at a pilot-scale plant and a calibrated set of values was obtained for four parameters: the maximum biofilm thickness, the detachment rate, the maximum autotrophic growth rate and the oxygen transfer rate.

Oxygenation performance of a laboratory-scale Speece Cone hypolimnetic aerator: preliminary assessment

2008 ◽  
Vol 35 (7) ◽  
pp. 663-675 ◽  
Author(s):  
K. I. Ashley ◽  
D. S. Mavinic ◽  
K. J. Hall
Keyword(s):  
Oxygen Transfer ◽  
Gas Flow ◽  
Oxygen Transfer Rate ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Future Research ◽  
Hydraulic Residence Time ◽  
Two Phase ◽  
Inlet Velocity ◽  
Outlet Port

A prototype laboratory-scale Speece Cone hypolimnetic aerator was used to examine the effect of oxygen input rate and outlet port water velocity on oxygen transfer, using four standard units of measure for quantifying oxygen transfer: (i) the oxygen transfer coefficient at 20 °C, KLa20 (h–1); (ii) the standard oxygen transfer rate (SOTR) (g O2·h–1); (iii) the standard aeration efficiency (SAE) (g O2 kW·h–1); and (iv) the standard oxygen transfer efficiency (SOTE) (%). The maximum inlet velocity (i.e., 70 cm·s–1) was only 23% of the recommended design velocity (i.e., 305 cm·s–1), and the two-phase bubble swarm did not properly develop inside the cone, but remained as a gas pocket at the top of the cone, resulting in a drastically reduced bubble surface area to water ratio. Therefore, all of the performance measures from this prototype Speece Cone were much lower than would be expected with the recommended design inlet velocity of 305 cm·s−1. Despite this difference, the system was still capable of oxygen transfer efficiencies of about 61%, under low gas flow rates, which is still higher than any full-lift design hypolimnetic aerator operating on air. Future research efforts are focused on building a pilot-scale Speece Cone, with as close to the correct inlet and outlet velocities, hydraulic residence time, and physical dimensions as possible, such that a two-phase bubble swarm could be generated. Once this experimental data is collected and analyzed, it can be properly compared with predictive models.

Oxygen Transfer Characteristics in a Pilot Scale Surface Aeration Vessel with Simcar Aerator

2001 ◽  
Vol 22 (1) ◽  
pp. 57-68 ◽  
Author(s):  
M. Lee ◽  
J. Kang ◽  
C.-H. Lee ◽  
S. Haam ◽  
Hun-Hwee Park ◽  
...  
Keyword(s):  
Oxygen Transfer ◽  
Pilot Scale ◽  
Surface Aeration ◽  
Transfer Characteristics ◽  
Scale Surface

Aeration performance of hydrodynamic flow regulators

2013 ◽  
Vol 67 (12) ◽  
pp. 2692-2698 ◽  
Author(s):  
P. Wójtowicz ◽  
M. Szlachta
Keyword(s):  
Oxygen Transfer ◽  
Oxygen Transfer Rate ◽  
Pilot Scale ◽  
Hydrodynamic Flow ◽  
Oxygen Absorption ◽  
Discharge Mode ◽  
Wide Range ◽  
Aeration Efficiency ◽  
Aeration Performance ◽  
Aeration Capacity

Hydrodynamic flow regulators are used in environmental engineering as a replacement for traditional flow throttling devices. They are extremely efficient, reliable and free from the common disadvantages of traditional devices. Recent research by the authors indicated that the atomization of a liquid by hydrodynamic flow regulators accelerates oxygenation and may be used for improving the quality of wastewater and stormwater. To date, an evaluation of the aeration capacity of a hydrodynamic flow regulator at the pilot scale or in a practical situation has not been presented in the literature. This study presents the experimental results of oxygen absorption tests for conventional and modified cylindrical hydrodynamic flow regulators (patent pending). These devices were tested in a closed-circuit experimental setup at the semi-commercial scale. The aeration efficiency of hydrodynamic flow regulators was assessed by means of the overall standard oxygen transfer coefficient (KLa(20), h−1) and standard oxygen transfer rate (SOTR, gO2/h) for a wide range of tested configurations. The effect of flow rate and discharge mode on the aeration capacity of flow regulators was investigated. The values of KLa(20) for cylindrical hydrodynamic flow regulators obtained in the experiments were between 2.62 and 15.57 h−1 while SOTR values ranged from 53 to 316 gO2/h. The modified discharge mode with two active outlets allowed for an increase in aeration efficiency of up to 15% compared to conventional designs.

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