Technical | 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.
| Step | Process |
|---|---|
| 1 | The density gradient is loaded into the rotor while it is at rest. |
| 2 | As the motor is gradually accelerated, the gradient reorients itself vertically along the outer wall of the rotor assembly. |
| 3 | Once at operating speed, sample fluid is pumped into the rotor on a continuous flow basis. |
| 4 | The sample particles sediment radially into the gradient of increasing density. They eventually 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 | The gradient reorients itself to the original position without disturbing the particle bands. |
| 7 | The banded particles are now ready to be unloaded. Fractions are collected using air or water pressure and a pump to control flow. |
