Thermo Scientific HyPerforma 2.1 S.U.B., Руководство по интеграции оборудования

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Thermo Scientific Single-Use Systems Integrator’s Guide | 10
These hazardous conditions must be avoided in order to ensure
reliability. Using safety interlocks and agitation speed governors
eliminates the chance of human error.
The amount of liquid in the vessel and the amount of power applied to
the impeller have an impact on the applied deflection on the drive shaft.
This, and other improper use of the system, might cause the drive shaft
to break, which could damage the BPC, compromise sterility, and result
in the loss of a cell culture batch.
Speed governors are required for 2,000 L bioreactor systems. For
more information about using P/V ratios for bioreactor systems, see
the next section of this chapter.
WARNING: Safety interlocks should be used to stop agitation when
the volume falls below the minimum (50% of the rated volume for
the 2.1 bioreactor system and 20% of the rated volume for the 5.1
system). These interlocks will prevent running the system outside of
recommended volumes, which could damage the hardware and the
BPC, and result in the loss of a cell culture batch.
Agitation rate calculations
Using power input to volume (P/V) ratios
Using power input to volume ratios for agitation speed
The power input to volume ratio (P/V) allows for scale-up or scale-
down of bioreactor platforms by equating mixing power between
differently-sized systems. P/V is the most broadly accepted method
for determining a practical scale-up approach for agitation speed in
stirred tank reactors used for animal cell culture. This relationship is
dependent on the density of the liquid in the system (
ρ
), the inherent
power number of the impeller (Np), the diameter of the impeller (Di),
the volume of liquid in the vessel (V), the speed of the drive shaft in
RPM (n), and the power input to the liquid (P).
This relationship can be rearranged to solve for mixing speed as a
function of the other variables.
For known values of P/V, impeller power number, density, and
impeller diameter, this equation can be simplified by consolidating all
other values into a single coefficient (A).
Chapter 1
| S.U.S. Configuration Guidelines