5 Optional modules
Operating manual mzr-11507
Last update: August 2016
Technical data subject to change without prior notice!.
15
5.1
Fluidic seal module
Fluidic seal module
liquid outlet
(pressure side)
seal liquid
outlet
seal liquid
inlet
liquid inlet
(suction side)
tube
cartridge
Figure 6
Design of the micro annular gear pump with fluidic seal module
The role of the fluidic seal module is to prevent moisture and oxygen in the
surrounding atmosphere from penetrating into the pump. This eliminates the
risk of unwanted chemical reaction between the atmospheric gases and the
handled liquid (such as for example the crystallization reaction). The module
limits at the same time the possibility for the manipulated liquids to escape
from the pump.
The function of the fluidic seal module
The shaft sealing employed in the high performance micro annular gear pump
is designed in a way that allows for
the formation of a boundary layer in which
the delivered liquid comes into contact with the surrounding environment.
Small amounts of water vapor and oxygen may penetrate through the
protective boundary liquid film into the pump. The fluidic seal module enables
to control this influx - only a chosen and compatible liquid may come into
contact with the delivered liquid. The fluidic seal module prevents also the
inverse movement of the liquid - from the pump to the environment - which
could otherwise not be excluded.
With the fluidic seal module, a second sealing is added to the existing shaft
sealing. A cylindrical chamber with input and output openings displaced by
180° is located between the two seals (see figure 7). When the chamber is filled
with an appropriate sealing liquid, the manipulated liquid does not enter into
contact with water vapor and oxygen, but dilutes at a small ratio in the sealing
liquid. The dilution ratio depends on the existing pressure relations and drops
with increasing viscosity.
