Geometrical Models
The right geometry for every application  it's possible with the NETZSCH modular design! The NEMO® Pump belongs to the family of rotary positivedisplacement pumps. The two conveying elements are comprised of the fixed stator and the rotor which turns within it. The design is modular since the outer dimensions
of the pumps are identical, as are the connections on the
suction side and the discharge side, for all four geometries.
With the exception of the rotor and the stator, all other
components are also identical. This means that, if it is
ever necessary to adapt a NEMO PUMP® to new flow rates
or pressures after installation, this can be done by simply
exchanging the rotor and stator to better suit the new conditions. S/L Geometry The helical eccentric screw/rotor has a circular cross section, a very long pitch and large thread depth. It oscillates in the fixed stator, which has an internal thread with the same profile as the rotor, but with 180° interval twin starts and twice the pitch. As
a result of this 1/2 ratio lobe geometry, cavities are formed
between the rotor and the stator when the two are put together.
When the rotor turns within the stator, the progressing
cavities between the two transport the medium in a smooth
and continuous manner from the suction to the discharge
side of the stator. The 2stage NEMO® Pump in SGeometry can reach differential pressures of up to 12 bar at a flow rate of 100%. A singlestage NEMO® Pump in LGeometry has the same outer dimensions as the 2stage pump in SGeometry, the same diameter and eccentricity, but twice the pitch of the rotor/stator. This pump therefore produces a flow rate of 200% over the SGeometry at a differential pressure of up to 6 bar.
D/P Geometry The helical eccentric screw/rotor has an elliptical cross section, a long pitch and large thread depth. It turns in a circular eccentric motion within the fixed stator, which has an internal thread with the same profile as the rotor, but with 120° interval triple starts and 1.5 times the pitch. As a result of this 2/3 ratio lobe geometry, cavities are formed between the rotor and the stator when the two are put together. When the rotor turns within the stator, the progressing cavities between the two transport the medium in a smooth and continuous manner from the suction to the discharge side of the stator. The cavities in D/PGeometries are about 75% of the size of those in S/LGeometries, but they are passed through twice per revolution instead of only once, resulting in a flow rate 50% higher. The flow rate is determined by the pitch of the rotor/stator, the elliptical diameter and the eccentricity, as well as by the pumping rotation speed. The pressure capability depends on the number of stages, with the differential pressure being up to 6 bar per stage. The 2stage NEMO® Pump in DGeometry can reach differential pressures of up to 12 bar at a flow rate of 150% over that of the SGeometry. A singlestage NEMO® Pump in PGeometry has the same outer dimensions as a 2stage pump in DGeometry, the same ellipse and eccentricity, but twice the pitch of the rotor/stator. This pump therefore produces a flow rate of 300% over that of the SGeometry at a differential pressure of up to 6 bar.
