Case study

Volume flow measurement for monitoring the volume flow in an evaporative cooler
Cement plant | AirFlow P
Customer: Cement plant in Germany
Installation: In the inlet of the evaporation cooler
Product: Different dusts
Function: Monitoring of the air volume for more process safety and energy savings


Almost every cement plant needs an evaporative cooler to cool the exhaust gases for the cleaning process. In order to operate the evaporation cooler with maximum efficiency, a stable volume flow is required. Monitoring the volume flow also leads to energy savings, as external air supply units can be adapted (throttled) to the existing volume flow.

Due to the difficult process parameters, it is impossible to use differential pressure measurements on the evaporative cooler. Optical measuring devices also quickly reach their limits here due to the high dust load.

Until today, the air velocities are either not controlled at all or are controlled with the help of an optical measuring device. In many places, the fans are also run permanently at high load, which brings with it a huge potential savings.

Process data

  • Dust load: 5-10 g/m³
  • Diameter: 3600 mm
  • Process temperature: 250 °C – 500 °C


The AirFlow P high temperature version is a sensor specially designed for measuring air flow in dusty applications at high temperatures. It determines the air velocity based on the dust particles in the process. The evaluation unit (MSE300) calculates the measured velocity with an entered line area (v x A = m³/h). This makes it possible to obtain an air volume in m³/h or a velocity measurement in m/s with the AirFlow P. The sensor, featuring an electrodynamic measuring principle, measures the discharges of the passing dust particles and correlates these signals.

Thanks to the AirFlow P, in this application, the existing optical measurement was replaced, and a permanent and maintenance-free control of the process was implemented.


  • Loadable volume flow measurement despite high dust content in the line
  • Energy savings by controlling the process
  • Cost savings due to the elimination of maintenance work on the measurement technology

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