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5 Modular system
Operating manual mzr-7240
14
Technical data subject to change without prior notice!
Last update: March 2019
5.1
Fluidic seal module
The module can be employed for liquids which tend to crystallize, when air
contact is given. The module prevents reactions by covering the outcoming
shaft by a fluidic ambience.
Fluidic seal module
liquid outlet
(delivery side)
sealing liquid
outlet
sealing liquid
inlet
liquid inlet
(suction side)
liquid supply tube
cartridge
Figure 6
Design of the micro annular gear pump with fluidic seal module (figure with mzr-7245 S +S)
(layout on the right: with the optional sealing liquid delivery set)
The module can be applied for liquids which tend to react or crystallize in
contact with gases such as oxygen or water. The use of a fluidic seal module
has to be confirmed with the pump manufacturer.
Functioning of fluidic seal module
Based on the pump design in the rotary shaft seal there is a liquid boundary
film where the liquid is in contact with the ambient. Here small amounts of
ambient humidity or oxygen can penetrate into the pump getting over the
sealing lip. To prevent penetrating molecules from outside into the pump but
also hazardous substances coming out of the pump the fluidic seal module was
designed.
For this reason a second rotary seal is added to the pump which is located in
the fluidic seal module. Between the two rotary seals a fluidic chamber (see
figure 7) is formed which is filled with a sealing liquid compatible to the
pumped liquid. The fluidic seal module has two ports opposite to each other
for filling and degassing. A pressure head can be applied to the sealing liquid to
assure a support of the sealing function. In certain cases the sealing can be
flushed.
The sealing liquid will dilute the pumping liquid during operation with a
dilution ratio of approx. 1:1,000,000. The sealing liquid has to be compatible
with the delivered liquid and has to be determined in interdependence. A