rotary lobe pump


Compact design, high performance density and easy full service in place  – what is most convincing for you?

Rotary lobe pumps belong to the group of rotating positive displacement pumps. Thanks to their compact design, high performance density and operational safety they are often used to continuously and gently convey and dose - in proportion to speed - difficult media.

Functioning of a rotary lobe pump

The rotation of the rotors causes negative pressure on the suction side drawing the media in and transferring it along the housing walls to the pressure side. Elastomer rotors seal the pump off when the pump comes to a halt. If the rotors are made of metal the desired undersize prevents complete sealing. An exception is created by the bi-lobe metal rotors of the TORNADO T2 made by NETZSCH due to their elastomer pads on the rotor edges.

Characteristics of a rotary lobe pump

Rotary lobe pumps are equally suitable for low and high-viscous media. Due to their large free ball passage and low rotational speed they are relatively tolerant to blockage and solid materials in the medium. Varying solid content and thereby caused pressure variations are no factor to the flow. Their performance capacity is higher than that of many other positive displacement pumps of the same type. As energy is the most decisive factor of life cycle costs this is one of the most important benefits of this pump technology.

TORNADO T2 / revolutionary design for prolonged lifetime
The special design aiming at ruggedness and long lifetime combined with minimal maintenance effort is based on a revolutionary reversed material combination: Instead of elastomer rotors turning in a metal casing, rotors made of hardened steel are turning in a simply exchangeable elastomer housing-liner. As steel is less prone to material fatigue caused by dynamic forces, the lifetime of the rotors is significantly extended. Furthermore the metal of the rotors is less affected by changing temperatures allowing for smaller tolerances between them, leading to a higher performance capacity of the pump. As a side effect the pump can be operated at lower speed, decreasing wear and protecting all components.

Range of applications of a rotary lobe pump

Rotary lobe pumps are preferably used for media with the following characteristics

  • solid-loaden or free of solids
  • low to high viscosity  (1 mPas to 50.000 mPas)
  • shear-sensitive
  • abrasive
  • lubricating and non-lubricating

Technical features of a rotary lobe pump

  • compact design
  • various helical lobe designs and straight bi-lobe rotors
  • wide selection of materials for housings, liners and lobes
  • wide selection of seals

Benefits of a rotary lobe pump

  • flow rate in proportion to speed
  • precise dosing
  • continuous flow
  • low pulsation
  • large free ball passage
  • high performance density
  • easy maintenance thanks to free access to all conveying elements
  • change of rotation causes reversal of flow

Delivery characteristics of a rotary lobe pump

  • Flow rate up to 1000 m³/h
  • Pressure up to 10 bar
  • Speed: up to 500 rpm
  • Free ball passage: up to 70 mm

Hygienic rotary lobe pumps for food and pharma industry

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