New Performance Testing Facility for Large Centrifugal Fans

Author: Joachim Schürmann, Ventilatorenfabrik Oelde GmbH

Ventilatorenfabrik Oelde GmbH (Venti Oelde) has built a new performance testing facility for centrifugal fans, both heavy-duty and special construction, in a record time of only three months.

New performance testing facility

The new performance testing facility for single and double inlet centrifugal fans was commissioned by Venti Oelde in June. An international plant manufacturer attended the successful premiere.


New dimensions in measuring

Until now, Venti Oelde tested the aerodynamic and mechanical properties of fans under laboratory conditions and with elaborate individual measurements. The facilities and the locality also permitted measurements only on fans of a limited size. Now testing is carried out under operating conditions. Venti Oelde can now also perform a verification of the performance of large and special fans before their despatch. Customers, therefore, receive the desired proof of the aerodynamic data and running properties before commissioning.

Flow simulation to inlet box testing facility

Video: Conditioning of the flow profile within the measuring device

Flexible application according to fan type

In the new performance testing facility for centrifugal fans it is possible for Venti Oelde to arrange the measuring devices, depending on requirement, on the inlet or on the outlet side. Furthermore, the plant allows the rotating speed to be easily adjusted during a performance measurement. This means that the fan manufacturer can systematically test all configurations according to the designated installation situation and the specific requirements of each individual customer.

The foundation of the testing facility includes a sophisticated slide-rail system which permits fans of various configurations to be flexibly attached to the foundation. Even centrifugal fans which are intended to be mounted on a raised concrete foundation can be fixed to and tested on it.

Construction and dimensions of the new measuring devices comply with standard DIN ISO 5801, whereby measurements and evaluation are performed in accordance with DIN ISO 5802 (VDI 2044). Measurements to similar international standards are also possible.

Diagrammatic arrangement of the performance testing facility:
1 | Inlet chamber with throttling device
2 | Cell rectifier or star rectifier
3 | Connections for measuring equipment
4 | Transition piece
5 | Centrifugal fan with inlet box
P | Pressure
T | Temperature
V | Velocity

Precise measurements with setpoint/actual value comparison

In the ultimate layout stage all aerodynamic and mechanical measurement data, such as, for example, temperature, pressure and vibrations are centrally collected. A calibrated measuring transducer transfers the data to an evaluating unit which directly visualises, records and reads out all the results. The time-consuming manual recording of the measurement values, which is otherwise usual, is no longer necessary. If wished, additional reference measurements, such as with the Prandtl tube, may be performed in the test facility.

Comparison of design values with measured values

Powerful performance on separate ground

Assembly, preparation and measurement of the centrifugal fans take up several days. So as not to hinder the production process, the new testing facility has been built in a separate area of the premises. An 800 kVA transformer station, upgradable to 1600 kVA, was specially installed to provide the necessary connection to the power supply. It transforms the high voltage to 400 Volts, which are required for operation with a frequency converter.

The first construction stage permits the operation of drive motors with a rated output of 630 kW with frequency converter. The plant has been so designed that drive motors up to 1200 kW can be operated with converter.