Device for the measurement of high volume flows at high temperatures in industrial furnaces
Within the scope of this project it was possible to develop a continuously operating volumetric flow measuring device for convective heat treatment plants. The findings from the predecessor project 16314, in which a volumetric flow measuring device (measuring cross) for radial fans with backward curved blades and symmetrical incoming flow was developed, serve as the basis. The newly developed measuring nipples are also mounted in the inlet nozzle and function for all common fan types (radial fans with forward and backward curved blades, drum rotors, axial fans).
For this purpose, the basic flow conditions in the inlet nozzle for the four fans investigated were measured with a 5-hole probe. The analysis of the flow profiles shows that there is a measuring position for both centrifugal and axial fans at which the volume flow can be measured independently of the operating point. This representative measuring point is used by the developed volumetric flow measuring device.
Four measuring nipples were installed in the inlet nozzle of the fans. Investigations in four operating points of each of the three radial fans showed that the measuring nipples can measure the volume flow with high accuracy. Even a (very unfavourable) asymmetrical inflow does not impair the function of the measuring nipples. The calibration factor is constant for all examined centrifugal fans.
The measuring nipples were also examined on axial fans, the case of a change of flow direction should also be covered. A constant calibration factor can also be determined for suction-side measurements with measuring nipples in the inlet nozzle. The measuring nipples must be modified for use in case of a change of flow direction. In this case, the calibration coefficient for the pressure-side measurement depends strongly on the delivery number.
The measuring nipples were then successfully subjected to a practical test in two real systems under operating conditions.
Publications within the project
Strämke, S.; Perkowski, D.; Pfeifer, H.: Messsonden zur Volumenstrommessung in Thermoprozessanlagen, gwi gaswärme international, 66 (2017), Nr. 6 Dezember, S. 55-60
The IGF project 18201 N of the Forschungsvereinigung Forschungskuratorium Maschinenbau e.V. was funded by the AiF within the framework of the programme for the promotion of joint industrial research (IGF) of the Federal Ministry of Economics and Energy on the basis of a resolution of the German Bundestag.
Further information and the final report can be obtained from the Forschungskuratorium Maschinenbau e.V., Lyoner Straße 18, 60528 Frankfurt, Germany or firstname.lastname@example.org