With this program you can design different kinds of bioreactors. Therefore are three different parts available in the application. In the upper left part, the parameters can be found. In the upper right part the designed bioreactor is shown. In de lower part is a spreadsheet section where the results of the calculations are shown.
In this section you can fill in all the diverse parameters of the bioreactor. These parameters are not only the dimensions of the bioreactor but also information about the fermentation broth and the gas flow and headspace pressure. All the calculations are based on the stirrer speed.
In this section a schematic drawing of the bioreactor is shown.
The drawing changes simultaneously, when a parameter is changed in the Parameter section. By clicking the checkbox in the drawing section, the working volume is corrected for the largest calculated hold up.
In this case the color of the working volume will be darker than without the correction. If the working volume corrected for the hold up is larger than the total volume, the color will change to red.
In the spreadsheet all calculated results are
shown. If a parameter in the Parameter section is not available, the result column will stay
empty.
The calculated results can be used in other programs like Excel. Therefore cells must be
selected. Cells can be selected by moving the mouse over the spreadsheet when the mouse button is
pressed. Or a row can be selected by clicking on the first cell of a row. The whole spreadsheet can be selected by clicking on the top left part of the spreadsheet.
There
are several parameters to design your vessel. If you change a parameter, others
are simultanously recalculated. During recalculation, the lightblue parameters
are used as constants. To make a parameter constant, click on the C-button right
from the parameter.
If you
move the mouse over a parameter, an explanation of that parameter is given in
the yellow box.
The
vessel parameters are:
V: |
the total volume of the vessel, in m3 |
Hv/Tv: |
height of the vessel devided by the diameter of the vessel |
Hv: |
the height of the vessel, in m |
Tv: |
the diameter of the vessel, in m |
Vw/V: |
the working volume devided by the total volume |
Vw: |
the working volume of the vessel, in m3 |
Hw: |
the level of the liquid, in m |
Tv/D: |
the vessel diameter devided by the diameter of the stirrer |
D: |
the diameter of the stirrer, in m |
Nstir: |
the number of stirrers between 1 and 3 |
Hs1/D: |
the position of strirrer 1 from the bottom of the vessel devided by the
diameter of the stirrer |
Hs1: |
posistion of stirrer 1 from the bottem of the vessel, in m |
Hs2/D: |
the position of strirrer 2 from the bottom of the vessel devided by the
diameter of the stirrer |
Hs2: |
posistion of stirrer 2 from the bottem of the vessel, in m |
Hs3/D: |
the position of strirrer 3 from the bottom of the vessel devided by the
diameter of the stirrer |
Hs3: |
posistion of stirrer 3 from the bottem of the vessel, in m |
Hs/D: |
the height of the stirrer blade devided by the diameter of the stirrer |
Hs: |
the height of the stirrer blade, in m |
Nbaffles: |
the number of baffles in the vessel |
Np: |
the power number of the stirrer |
start
rpm: |
the starting speed of the calculation in rounds per minute |
delta rpm: |
steps of increasing the speed of the stirrer during calculation in
rounds per minute |
For the
power number you can add a value direct in the text box, but you can also choose
one value from a window with power numbers of different kinds of stirrers. For
this option click on the ? button next to the Np text box; (ref: Bioreactor
Design, by Klaas van 't Riet and Johannes Tramper; ISBN 0-8247-8446-4).
To add
or change the gas and liquid parameters. The parameters in gray can not be
changed, those are calculated on base of another parameter.
The parameters are:
Pa: |
the airpressure in the headspace |
Ps1: |
the calculated pressure at the height of stirrer 1 |
gasflow: |
the gasflow in L/min |
gasflow: |
in volume gas per
working volume in min-1 |
gasflow: |
the calculated gasflow in m3/s |
rho: |
the density of the liquid in kg/m3 |
nl: |
the liquid dynamic viscosity in N s m-2 |
vl: |
the liquid kinematic viscosity in m2 s-1 |
The
calculated parameters are:
Nrpm: |
the stirrer speed in rotations per minute |
vtip: |
the speed of the stirrertip in m/s |
Re: |
the Reynolds number |
SLP Ps: |
the stirrer(s) power consumption in a single liquid phase in |
SLP Ps/Vw: |
the stirrer(s) power consumption in a single liquid phase devided by the
working volume in |
SLP tm: |
the mixing time in a single liquid fase in seconds |
GLP Ps: |
the stirrer(s) power consumption in a gas - liquid phase in |
GLP Ps/Vw: |
the stirrer(s) power consumption in a gas - liquid phase devided by the
working volume in |
GLP tm: |
the mixing time in a gas - liquid phase in seconds (shown in the second
column). |
Df/D: |
the forced vortex zone diameter / stirrer diameter |
Yave: |
the time average shear rate in per second |
Ymax: |
the maximum shear rate in per second |
eddy
length: |
the smallest turbulent eddy length in m |
kolA
coal: |
the oxygen transfer coefficient in coaliscing nonviscous liquid in per
second. This value has a accuracy
of approximately 30%. |
kolA
noncoal: |
the oxygen transfer coefficient in noncoaliscing nonviscous liquid in
per second. This value has a
accuracy of approximately 30%. |
Hold
up: |
the gas hold up in the working volume in a percentage of the working
volume. |
In the Oxygen Transfer Rate window, the Oxygen Transfer Rate (OTR) is calculated as function of the stirrer speed and different percentages dissolved Oxygen.
To calculate the amount of oxygen in 1 cubic
meter gas, the ideal gas law is used: PV = nRT. (For P the pressure at
stirrer 1 is used)
The partition coefficient is used to calculate the amount of oxygen in the
liquid.
In the top part of the window the variables can be defined.
|
the percentage of Oxygen in the gas phase |
m: | the partition coefficient |
Cogl: | the oxygen in the interface between gas and liquid in mol/m3.This variable is calculated on the basis of the other variables |
T: | the temperature in Kelvin, degrees Celcius and degrees Fahrenheit |
There are 2 kinds of spreadsheet which shows values of the OTR as a function of the stirrer speed and KolA (first and second column) and various percentages dissolved Oxygen. These percentages are shown in the headers of the spreadsheets. The two spreadsheets give the OTR in a Coalescing Nonvisous Liquid and in a Noncoalescing Nonvisous Liquid. Both OTRs are in mol m-3 s-1.
The menu of the application contains the following items:
New
Open
Save as
Exit
To open the Oxygen Transfer Rate calculation window
Help - General Text
Help - Oxygen Transfer Rate - To show the Oxygen Transfer Rate help file
Help - Drawing
Registration
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