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Solution Plots Growth

tobistark edited this page Nov 19, 2014 · 10 revisions

Process Variables

In the plot process variables, the graphs show the temperature and total solvent and antisolvent mass profile, respectively.

The temperature graph can be separated into three regions:

Region I: strong linear decrease of temperature
Region II: constant temperature
Region III: lower linear decrease of temperature

The total mass stays constant throughout the process.

Concentration plot

Region I: Increase due to temperature drop in subsaturated state
Region II:
Region III: After certain time, saturated state is reached.
From that point on, the concentration decreases due to growth of crystals.

Supersaturation plot

Region I: monotonous increase due to temperature drop
Region II: constant when neither temperature nor total mass changes
Region III: increase to 1 and afterwards balance according to the following relation

where all of the time the decrease in the denominator prevails over the decrease in the nominator.

Operating system plot

In this plot the concentration is shown dependent on the temperature. Basically, the information from the concentration and supersaturation plot are respresented in one plot. The three regions mentioned above can be recognized again. Note that it can nicely be seen that our process starts in the subsaturated domain.

PSD cumulative properties

In this plot, the 0-th and 3-rd moment of the distribution and the volume average length are plotted. The moments are defined as

and the volume average length is defined as

.

PSDs 3D (time evolution)