Thermo Scientific
Single-Use Systems Integrator’s Guide
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9
Chapter 1
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S.U.S. Configuration Guidelines
Single-use systems
(S.U.S.) configuration
guidelines
1.1 Maximum agitation rates for
Single-use bioreactors
Using agitation speed governors and safety
interlocks
Agitation speed governors must be set up on Single-Use Bioreactor
(S.U.B.) controllers to limit the maximum mixing speed, according to
pre-defined liquid volumes. Safety interlocks, which stop agitation
when the volume in a S.U.B. drops below defined limits, and speed-
based governors prevent damage to the drive shaft in the bioreactor.
We recommend the use of speed governors and safety interlocks to
prevent the hazardous conditions listed below.
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Operating the motor at any speed while loading the drive shaft.
•
Operating the agitator when volumes are less than 50% of a sys-
tem’s working volume for mixers, fermentors and 2.1 bioreactors, or
below 20% of a system’s working volume for 5.1 S.U.B. systems.
•
Operating the agitator above the recommended speeds based on
qualified power input to volume (P/V) thresholds (see the next sec-
tion of this guide).
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