D-Series Syringe Pumps - Isco

D Series Syringe Pumps
Section 9 Modifier Addition
9.1 Introduction The Teledyne Isco modifier addition systems utilize two D Series
syringe pumps regulated by one controller to deliver a mixture of
supercritical fluid and modifier to one or more Model SFX 2-10,
SFX 220, or SFX 3560 extractors.
Note
The configurations described in this section apply to 65DM,
100DM, 100DX, 260D, 500D, and 1000D pumps that use Valco
or SSI fittings.
The 65D pump can be configured and operated in a similar
manner. However, due to the higher operating pressure and
the AE F250C fittings, the 65D requires hardware that is not
listed in this section. Call the factory for details to configure a
65D pump for this type of operation.
Pump A delivers supercritical fluid while pump B meters modifier.
Both fluids pass through one-way check valves before they
meet and are blended together in a mixing tee. Modifier concentrations
of up to 100 percent (v/v) are programmable via the controller.
If higher concentrations are needed, put the modifier in
pump A to be delivered as the primary fluid.
Both pumps operate in constant pressure mode and will flow up
to their maximum rate to maintain the set pressure. When modifier
addition mode is selected and the RUN key is pressed, pump
A pressure is ramped at its maximum flow rate to the set
pressure while pump B waits at a lower pressure (3.5 bar).
The user can increase the pump B minimum pressure if the modifier
boils at room temperature and 3.5 bar. See Section 9.4, Modifier
Addition.
Once pump A has reached the set pressure, the controller will
enter a hold mode and wait for a pressure drop, with opening the
extractor inlet to signal the start of “EQUILIBRATION,” or the
user can press the “RUN” key to start equilibration.
Note
Flow must then be started through the system by opening all
valves! The modifier pump will not equilibrate properly without
flow.
Then pump B pressure is slowly ramped upward until its check
valve is detected to open. At this point, the controller exits
“EQUILIBRATION” mode and displays the message
“RUNNING” on the front panel display.
9-1