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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.

Parameter section

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.

Drawing section

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.

 

Spreadsheet section

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.

Using Parameters

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.

Bioreactor parameters

Vessel parameters

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).

Gas Liquid Variables

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

Calculated results

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
If the Reynolds number < 10 000 (the mixing isn't turbulent) the color of the calculated value is red

SLP Ps:

the stirrer(s) power consumption in a single liquid phase in Watts

SLP Ps/Vw:

the stirrer(s) power consumption in a single liquid phase devided by the working volume in Watts .

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 Watts (shown in the second column).

GLP Ps/Vw:

the stirrer(s) power consumption in a gas - liquid phase devided by the working volume in Watts (shown in the second column).

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. 
If the working volume together with the hold up is larger than the total vessel volume, the calculated value is red

The calculated results can be used in other programs by copy the selected cells via Control-C.  

Oxygen Transer Rate window

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.

Variables

In the top part of the window the variables can be defined.

% O2 in gas:

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


Spreadsheets

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:  

The menu of the application contains the following items:

File

New - For starting a new design

Open - To open a saved design

Save as - To save a design

Exit - Quit the program  

OTR

To open the Oxygen Transfer Rate calculation window

Help

Help - General Text - To show the general help file.  

Help - Oxygen Transfer Rate - To show the Oxygen Transfer Rate help file

Help - Drawing - To show a drawing of the bioreactor.

Registration - To show the window where the registration code can be added.

About - To show the About window


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