SyriXus Series Pumps Installation and Operation Guide
Section 6 Modifier Addition
6-6
EAR99 Technology Subject to Restrictions Contained on the Cover Page
To Fill Pump A with
Supercritical Fluid
(Helium Head-Space
Tank)
1. Place the pumps in Independent Control - Constant Pressure
Mode, as detailed above.
2. Be sure the pumps are stopped.
3. Close the pump A outlet valve before opening the tank supply
valve and pump A inlet valve.
4. Press REFILL. Press softkey ‘A’ to designate that pump A is the
active pump (the pump being refilled). Pump A will fill with
pressurized fluid.
5. After pump A has refilled, wait 15 seconds before closing the
tank supply valve and pump A inlet valve. This will allow time
for the flow into the pump to complete.
6.1.5 Two-Pump
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. When the con-
centration requires a higher percentage of modifier than the other
fluid, it may be desirable to 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 RUN 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).
Pump B minimum pressure can be increased if the modifier boils at
room temperature and 3.5 bar.
Once pump A has reached the set pressure, the controller will enter a
Hold Mode and wait for a pressure drop. The start of EQUILI-
BRATION is signaled by opening the extractor inlet, or pressing RUN.
NOTE
Flow must then be started through the system by opening all valves!
The modifier pump will not equilibrate properly without flow.
Pump B pressure is then slowly ramped upward until its check valve
is detected as open. At this point, the controller exits EQUILI-
BRATION Mode and displays the message RUNNING.
When RUNNING is displayed, the controller monitors pump A piston
movement, and calculates the pump B piston movement required to
deliver the correct ratio of modifier. If pump A cannot maintain the set
pressure, as when the extraction cartridges are initially filling or
pump A is refilling, the controller reverts to EQUILIBRATION and
pump B pressure is dropped below that of pump A to avoid delivery of
incorrect modifier concentrations. Once the pump A set pressure is
reestablished, the system will re-equilibrate.
