Centrifugal Compressors



Next Turbo Technologies designs and manufacturers highest efficiency, modern integrally geared single stage turbocompressors for the aeration process focused mainly on the waste water treatment industry. We offer smart solutions in every aspect; from a passioned, experienced team.

Explore our Turbocompressor Portfolio and the related Automation solutions to find the perfect match for your plant requirements.


Integrally geared centrifugal turbo-compressors with the proven 2-point regulation is the most efficient aeration equipment available on the market. The product range features standard auxiliary components, which can be sourced locally and avoids special, high frequency electronic components.

The geometry and dimensions of the impeller define the compressor curve (see above dashed lines in diagram) and influences its absolute design efficiency. The impeller utilized is designed for the specific requirements and specifically suited for discharge diffuser vane operation (1-point and 2-point vane regulation control).
The impeller is milled out of a solid block of high strength aluminimum alloy and slightly backleaning for increased efficiency.


  • Flexibility in Automation; with high real-airflow-turndown of 40-100%
  • Highest efficiency over whole turndown range, due to diffuser vane regulation
  • Power optimization with 2-point regulation control
  • Offers more than 20 years of lifetime for your investment
  • Reliable operations due to robust mechanical design
  • Proven technology in waste water aeration application
  • Main auxiliaries standard and available on the market

Automation Every compressor is equipped with industrial PLC for the safety and control handling. The Local Control Panel (LCP) can be equipped in a seperate panel in combination with the Modular Enclosure or as an integrated compartment in the Compact Enclosure. If the supply comprises of more than one turbocompressor it is advisable to include a Master Control System (MCS) for the automatic control of the compressors in cascade mode via informations coming from the Central Control system or directly from the Process.

  • Industrial PLC with Standard components
  • Proprietary software
  • Standard comunication protocols
    • TCP/IP
    • Profibus/Profinet
    • Ethernet
    • MODBUS
  • Available standard brands:
    • Siemens
    • Allan Bradely
    • Schneider Telemecanique


Diffuser Control – Mechanical 1-Point Control This control mechanism is a 1-point control, regulating the airflow with mechanical outlet diffuser vanes ,changing the relative airflow vector and therefore relative air- speed with limited influence to the required pressure line. Effectively moving the compressor performance curve along the horizontal axis. No efficiency compensations for fluctuations in pressure and air characteristics (temperature, relative humidity) are provided. To add this control feature, refer to the 2-point-control mechanism below.

Diffuser and VFD Control – Electrical 2-point-Control Featuring the mechanical outlet diffuser blades, but extending the control range with its electrical 2-point control. A standard low frequency VFD is adjusting the speed within a limited bandwidth to adjust the compressor operation to pressure/ air quality fluctuations (e.g. temperature, relative humidity). Please note: the VFD is not used, as in regular 1-point speed controls, to regulate the airflow; it is a fine-tunding mechanism. The airflow regulation is handled by the outlet diffuser vane system.

Diffuser and Inlet vanes Control – Mechanical 2-point-Control Featuring the same 2-point mechanism as above, but utilizing two mechanical systems: the outlet diffuser vanes in combination with inlet guide vanes. The inlet guide system also adjusts for changes in pressure and air quality (e.g. temperature, relative humidity) by changing the pre-rotational angle of the inlet air flow. This is handled with contant speed. Compare the relative efficiency map to the right to see the differences.

Product Ranges


The Making of GTB Compressor: 3D Blower Animation: NTT 2 Point Control – Explained: Tutorial Diffuser Vs Speed: NTT Compact Enclosure: NTT Company: GTB Compressor with Compact Enclosure: