4 Description
Operating manual mzr-11507
Last update: August 2016
Technical data subject to change without prior notice!.
11
efficiency is dependent on the media and the pressure against which it has to
be fed.
Example
: The pump head mzr-11507 has a displacement volume of 192 µl. On
the assumption that the volumetric efficiency is 100%, the flow rate at a speed
of 3000 RPM would be 576 ml/min, according to the above formula. The table
3 shows theoretical flow rate values depending on speed expressed in ml/min
and l/h.
RPM
Q
[ml/min]
Q
[l/h]
100
19,2
1,15
500
96
5,76
1000
192
11,52
2000
384
23,04
3000
567
34,02
4000
768
46,08
5000
960
57,60
6000
1152
69,12
table 3
Theoretical flow rate of the micro annular gear pump mzr-11507
The pressure, which the pump has to generate, is given by the construction of
the fluidic system and the results of the hydrostatic pressure and the hydraulic
resistants (given by tubes, contractions etc.).
The viscosity of the pumping medium has an important influence on the
volumetric efficiency. The volumetric efficiency increases with higher viscosity
according to the smaller disengagement through the gaps of the pump.
Cavitation is an effect, which can result in a specific ceiling speed. The reason
for this is the static pressure reaching the steam pressure of the liquid in the
inlet port of the pump. In this state an increase of speed does not result in an
increased flow rate. The formation of gas prevents a sufficient feeding of the
pump. With increasing viscosity of the liquid (e.g.> 10.000 mPas), the ceiling
speed is lower.
The specific feature of the
mzr
-pumps is their highly precise design, as well as
the guarantee of high accumulator pressure and high accuracy in flow rate and
dosage. Therefore, space width and transverse space width of the rotors as well
as the interspace to the adjacent case parts are in the range of just a few
micrometers. This precision is the condition to achieve a volumetric efficiency in
the range of approx. 100 %.
