Temperature Fractions

During the distillation we want to collect pure solvent in one receiver and have contaminants collected in separate receiver or left is the pot flask (boiler). Normally an automatic valve or automatic fraction collector is used to direct the distillate to the desired receiver depending on if it is a contaminant or pure solvent. This decision is usually made by observing the vapor temperature in the top (head) of the distillation column. If the temperature corresponds to the pure solvent then the valve can be activated to direct the solvent to the "pure solvent" receiver. Alternatively, if the vapor temperature corresponds to the contaminant, then the valve can be activated to send the contaminant to the the "contaminant" receiver.

The M690 microprocessor allows up to 8 temperature fractions to be collected for each solvent recycling protocol although 1 or 2 fractions is almost always sufficient. An automatic two way valve is most commonly used to direct the distillate. In some cases an automatic fraction collector with 4 or 8 places is used to direct the distillate.

Each temperature fraction has an "Open Cut" and a "Close Cut". The Open Cut is the temperature at which the fraction will begin to be collected and the Close Cut is the temperature at which the fraction will stop being collected. Up to 8 cuts or fractions can be taken for each solvent recycling protocol.

This allows maximum flexibility in optimizing each solvent recycling protocol.

Equilibration Time Heating Rate
Reflux Ratio
Auto Shut Down Temperature
M690 Parameters