Biomedical Engineering Reference
In-Depth Information
mixing applications. Not intended for sterile applications: suitable
applications include dissolving solid media and/or buffer compo-
nents prior to sterile filtration.
• Thermo Fisher Scientific HyClone Mixtainer Systems with an impel-
ler linked to an overhead drive and is coupled by a sealed bearing
assembly, which maintains the integrity of the system. The mixing
stirrer is installed off-center. This mixer is intended for powder-
liquid and liquid-liquid mixing and has sterile disposable contact
surfaces.
Tumbling Mixer
• Pad-Drive (ATMI Life Sciences), 25 L to 1,000 L, uses a tumbling stirrer
mounted from top; the wand rotates inside an inert polymer sleeve.
• WandMixer (ATMI Life Sciences), 5 L to 200 L, uses a tumbling stir-
rer whose axle is built into the bag from the top of the bag.
Oscillating Mixer
• Wave (GE Healthcare), 20 L to 1,000 L, horizontal oscillation on a
rocker. The rocking motion is very efficient in generating waves, and
the wave-induced motion in the bag causes large volumes of fluid to
move facilitating the dispersion of solids. The optimum operating
parameters depend on the combination of the container geometry,
bag support, filling volume, rocking angle, rocking rate, and the
characteristics of the mixture (solids, foam, etc.).
• HyNetics (HyNetics Corporation), 30 L to 5,000 L, vertical oscilla-
tion of a disk or septum. The key feature is the mixing disk, which
is fabricated from rigid, engineered polymers. Multiple, evenly dis-
tributed slots penetrate the disk. The underside of the disk incorpo-
rates pie-shaped flaps. These flaps open as the disk moves up from
the bottom of the mixing bag on the drive's upstroke, allowing fluid
to flow through the disk's slots. The flaps close on the downstroke,
forcing the liquid toward the bottom of the vessel and subsequently
up the walls of the vessel. The mixing disk, flaps, polymer mixing
shaft, and the shaft rolling diaphragm seal, which attaches to the
bag film, are disposable.
