Agilent Technologies Quaternary Pump 1100 Series - Manual (Page 201)

201
Introduction to the Quaternary Pump
Overview
Figure 42 Principle of the Quaternary Pump
When turned on, the quaternary pump runs through an initialization
procedure to determine the upper dead center of the first plunger. The first
plunger moves slowly upwards into the mechanical stop of chamber and
from there it moves back a predetermined path length. The controller stores
this plunger position in memory. After this initialization the quaternary pump
starts operation with the set parameters. The active inlet valve is opened and
the down-moving plunger draws solvent into the first chamber. At the same
time the second plunger is moving upwards delivering into the system. After
a controller-defined stroke length (depending on the flow rate) the drive
motor is stopped and the active inlet valve is closed. The motor direction is
reversed and moves the first plunger up until it reaches the stored upper limit
and at the same time moving the second plunger downwards. Then the
sequence starts again moving the plungers up and down between the two
limits. During the up movement of the first plunger the solvent in the
From solvent bottle
Inlet
valve
Outlet
valve
Damper
To mixing chamber
Seal
Chamber 1
Ball screw drive
Motor with encoder
Gear
To waste
Purge valve
Plunger 2
Chamber 2
Plunger 1