Zonal Density Gradient Reorientation

Gradient materials are loaded while the rotor is at rest, the flow is stopped and a linear density gradient is formed while the rotor is accelerating to a set speed.  Following a reorientation phase the gradient transitions from horizontal to vertical in the rotor.  After this transition occurs then the rotor can be accelerated to set speed while in a continuous flow operation.

Zonaldensity gradient reorientation

Step Process
1 The density gradient is loaded into the rotor while it is at rest.
2 As the rotor is gradually accelerated, the gradient reorients vertically inside the rotor assembly.
3 Once at the required operating speed, sample fluid is pumped into the rotor on a continuous flow basis.
4 The sample particles sediment radially into the linear density gradient. The particles band (iso-pycnically) in cylindrical zones where the gradient density equals a particle's buoyant density.
5 At the end of the run, the rotor is decelerated to rest.
6 During deceleration the gradient reorients itself to the original position without loss of resolution in the particle bands.
7 The banded particles are now ready to be unloaded. Fractions are collected using the Automated Fluid Handling System.

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