6 System integration
Operation manual mzr-2961, mzr-4661
Last update: April 2018
Technical data subject to change without prior notice!
21
6.4
Filter selection and use
In majority of cases it is recommended to integrate a filter on the suction side
of the micro annular gear pump to ensure its secure operation. The
recommended filter pore or mesh size should not exceed 10 µm. The
penetration of particles or swarf that could cause a blockage or damage to the
pump can only be avoided by using an adapted filter.
HNP Mikrosysteme offers a choice of standard filters covering a broad spectrum
of applications. You may count on our assistance for the selection of the most
suitable filter.
In order to select the best adapted filter, such operating parameters as the flow
rate, the viscosity and the degree of pollution of the liquid will be needed. An
increase in at least one of the mentioned terms will require the use of a bigger
filtering element or pressurization of the delivered liquid. In case no suitable
filter for the given high-viscosity liquid can be found, it is possible to use a filter
with slightly larger pore size. Prior discussion with HNP Mikrosysteme is here
recommended. A filter with larger pores is still better than no filter at all. As an
alternative solution an already filtered liquid may be used.
Warning
Because filters have a large internal volume, it is recommended to fill in the
filter and the induction (suction) tubing with already filtered liquid in order to
avoid a too long dry run of the pump during the first operation.
Warning
Please control regularly the filtering elements for pollution. Cleanse regularly
the filter or replace it with a new one. A polluted filter may considerably
decrease the volumetric efficiency of a pump. Furthermore, because of the
cavitation effects dosage imprecision and even pump damage may occur.
Warning
A too small filter (too little filtering surface) may considerably decrease the
volumetric efficiency of the micro annular gear pump. What is more, because
of the cavitation effects dosage imprecision and even pump damage may
occur.
