New screw pumps for a wide variety of media

Louise Smyth

Netzsch Pumpen & Systeme offers in its product range not only the progressing cavity pumps but also the rotary lobe pumps and the three model series of compact multi screw pumps: the NOTOS two, three and four-spindle pumps. Depending on the type, they are suitable for non-lubricating substances at high pressures up to 80 bar and temperatures up to 300°C.

The core feature of the screw pumps is their concept following the high-efficiency unique design (HEUD) and producing a proven improved force-performance ratio. This is due, on the one hand, to the very hard materials used – the choice ranges from simple grey cast iron to chrome-nickel steel and on to duplex or Hastelloy alloys – depending on the requirement. The stability of these materials ensures very minor sagging of the spindles, even under the high loads typical for screw pumps; this allows working with very narrow tolerances between dynamic and static parts in the manufacturing process. Possible back-flow from the higher pressure to the lower pressure side is thus reduced and the delivery efficiency increased at the same time.

The shape of the spindles has also been adapted to minimise interferences and resistances in the material flow. Netzsch used sophisticated calculation methods in this process, e.g. the finite element method (FEM), permitting a realistic simulation of the pump and the pumping process with freely configurable parameters. In this way, the spindle geometry for the desired delivery characteristics could be determined and medium transport largely free from turbulence and pulsation achieved.

Beyond this, the choice of materials and the design ensure high robustness and service life of the screw pumps. In addition, each pump from Netzsch is designed specifically for the respective application area, especially in terms of size. This exact matching of technology and equipment to the application allows adapting to the specific properties of the medium and also the loads – due to the type of deployment – early on and to largely compensate for influencing factors that could lead to increased wear or damage.

For more information visit Netzsch

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