Comparing these two cases leads to the conclusion that isothermal changes prevail in
phase separation surfaces and intensification of mass transfer under the influence of
variable pressures.
CONCLUSION
1. The presented mathematical formalizations point to the interconnections in the
dynamics of transformation and synthesis of substances according to the matter balances.
This means the ability to create a control system for synthesis processes based on tracking
the changes in concentrations of sugar, microorganisms, dissolved oxygen, ambient
temperature, etc.
2. Among the effective factors of influencing mass exchange processes in the
separation surface between the liquid and dispersed gas phases are the variable pressures
in the gas phase above the liquid and the limit of velocities in the created gas-liquid
circuits.
3. The general increase of pressure in the gas phase means the possibility of
increasing the oxygen saturation constant c
s
in order to intensify the mass transfer in these
processes.
4. Simulation of hydrodynamic aeration modes of culture media is achieved based
on the physical concept of reduced gas phase velocity.
5. Aeration of the medium with compressed air is accompanied by N
2
reverse in the
phase separation surface under the influence of hydrostatic pressures due to the saturation
of the liquid phase with nitrogen. This feature, in most cases, does not gather the attention
of modern researchers.
0
0,004
0,008
0,012
0,016
0,02
0,2
0,6
1
1,4 1,8
2,2
2,6
3
Figure 5. Dependency between the dissolution rate
of oxygen and the ratio of initial and fluid pressure
dM O
2
dτ
, kg/s
0
0,005
0,01
0,015
0,02
0,025
0,2
0,6 1
1,4
1,8 2,2
2,6
Figure 6. Dependency between the dissolution rate
of oxygen and the ratio of pressures: 1 – dissolved
oxygen concentration is 0.002 kg/mм
3
; 2 –
dissolved oxygen concentration is 0.001 kg/mм
3
1
Р
(in)
/Р
2
dM O
2
dτ
, kg/s
3
Р
(in)
/Р
- 1791 -