correspond to the height of liquid medium layer h being between 1 and 10 m. Calculations
are made for values ρ = 1000 kg/m
3
and g = 9.81 m/s
2
and presented in Table 2.
Table 2 Saturation constants of culture media with N
2
and O
2
as functions of
hydrostatic pressures with an external pressure of 0.1 MPa, kg/m
3
Temperature of the
medium, °C
Hydrostatic pressure, MPa/mmwg
0/0
0.02/2
0.03/2
0.04/4
0.05/5
Nitrogen
0
10
20
30
0.0229
0.0182
0.0151
0.0131
0.02748
0.02184
0.01812
0.01572
0.02977
0.02366
0.01963
0.01703
0.03210
0.02548
0.02114
0.01034
0.03435
0.02730
0.02265
0.01965
Oxygen
0
10
20
30
0.01470
0.01140
0.00930
0.00783
0.01764
0.01367
0.01160
0.00943
0.01911
0.01482
0.01210
0.01018
0.02060
0.01596
0.01302
0.01096
0.02205
0.01710
0.01395
0.01174
Temperature of the
medium, °C
Hydrostatic pressure, MPa/mmwg
0.06/6
0.07/7
0.08/8
0.09/9
0.1/10
Nitrogen
0
10
20
30
0.03664
0.02912
0.02416
0.02096
0.03893
0.03094
0.02567
0.02227
0.04122
0.03276
0.02718
0.02358
0.04350
0.03458
0.02869
0.02489
0.04580
0.03640
0.03020
0.02620
Oxygen
0
10
20
30
0.02352
0.01820
0.01488
0.01250
0.02499
0.01380
0.01580
0.01330
0.02646
0.02052
0.01674
0.01410
0.02793
0.02166
0.01767
0.01490
0.0294
0.0228
0.0186
0.0157
It should be expected that the nitrogen saturation of liquid phase corresponds to
hydrostatic pressure, and coinciding transfer directions of N
2
and O
2
correspond to mass
transfer intensification. The movement of the gas-liquid mixture in the circuits leads to the
supersaturation of liquid phase, which may result in reverse transfer of nitrogen to the gas
phase or formation of an additional gas phase based on it. In the first case, this means the
existence of linked opposite flows of N
2
and O
2
in the phase separation surfaces and the
mass transfer area. However, on the other hand, the reduction of hydrostatic pressures
leads to an increase in volumes of the dispersed gas phase and interphase surface. The
overall increase of gas retention capacity at each level of the medium is proportional to
the difference in hydrostatic pressures, whereas the effects on the mass transfer intensity
are due to the difference in the saturation constants presented in Table. 2. Achieving
saturation conditions means that the molecular flows in the phase separation surfaces are
aligned, but they continue to exist. Hence the conclusion about the continuous renewal of
dissolved nitrogen in the form of a secondary gas phase. It is logical to conclude that the
secondary gas phase is formed during aerobic fermentation mainly by the gases that
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