Aeration oxygen transfer rate

Aerator type Materials of constmction Oxygen transfer efficiency, OTE, % Oxygen transfer rate, OTR, g/(W-h)... 

The oxygen transfer rate for aerators is normally reported at standard conditions. Thus, ia order to make meaningful comparisons, the ORT under working or field conditions should be adjusted to standard conditions oxygen requirement for treatment (SORT) by means of... 

The SORT value when divided by the standard conditions oxygen transfer rate (OTR) given for a mechanical aerator yields the oxygen concentration required for treatment. 

CASE STUDY OXYGEN TRANSFER RATE MODEL IN AN AERATED TANK FOR PHARMACEUTICAL WASTEWATER... 

If you aerate a bioreactor, power consumption is much less than a non-aerated bioreactor. Oxygen transfer rate, OTR 6 X 10 3 kgm-3 Oxygen uptake rate, OUR 0.65 mmol 02 kg 1 cell Specific growth rate, umax 0.5 h 1... 

Calculate mass transfer coefficient in a 60 m3 fermenter with a gas and liquid interfacial area of a = 0.3 m2-m 3, given pbroth = 1200kg m-3. The small reactor has working volume of 0.18m3, 1 vvm aeration rate. Oxygen transfer rate (OTR) is 0.25kmol in 3 h 3. There are two sets of impellers, and flat-blade turbine types of impeller were used, HL= 1.2/),. Find the exact specifications of a large fermenter. 

Acetic acid Ethanol Acetobacter, Gluconobacter Vinegar with 10 to >20 %, >190,000 t year h yield -98% Aerobic cultivation at 100-m scale Frings aerator for high oxygen transfer rates [21,22, 38]... 

The interfacial area per unit volume a is, again, a difficult quantity to measure in a fermenter since it depends on the number and size of the air bubbles entrained in the fermentation broth. These, in turn, are dependent on such factors as the aeration rate, the rheology of the broth at that instant and the presence or otherwise of surfactants. As a result, the quantity KLa tends to be treated as a single entity in experimental measurements of oxygen transfer rates in fermenters. 

For surface aeration of static cultures, in a closed system, a void volume 10 times larger than the culture medium volume is necessary for adequate oxygen supply. In agitated cultures with surface aeration, oxygen transfer is dependent on agitation rate and impeller geometry. 

The first two methods are widely used just for laboratory-scale applications, since there are limitations for their use at larger scales. In surface aeration, the oxygen transfer rate is related to the liquid surface area (gas-liquid interface). When the culture scale is increased, maintaining constant geometric proportions, the volume increases with the third power of a characteristic linear dimension of the system, whereas the surface area increases with its square. 

Short-circuiting is one of the major problems associated with mechanical aeration equipment. Combined mechanical- and diffused-aeration systems have enjoyed some popularity for industrial-waste systems that treat variable organic loads. The mechanical mixers provide the fluid mixing with the diffused aeration varied for different oxygen-transfer rates. 

Matsuoka H, Fukada S Toda K (1992) High oxygen transfer rate in bubble aeration using hollow fiber membrane a proposal of a new aeration system. Biotechnology and Bioengineering 40 346-352. 

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