Flexim FLUXUS WD, Руководство по эксплуатации

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3 General principles
FLUXUS WD 3.4 Undisturbed flow profile
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UMFLUXUS_WDV1-3EN, 2018-07-16
Observe the following notes on the selection of the measuring point:
Horizontal pipe
Select a measuring point where the transducers can be mounted laterally on the pipe, allowing the sound waves to propa-
gate horizontally in the pipe. Thus, solids on the bottom of the pipe or gas bubbles in the pipe's upper part are prevented
from influencing the propagation of the signal, see Fig. 3.9 and Fig. 3.10.
Vertical pipe
Select the measuring point at a pipe location where the fluid flows upward. The pipe has to be completely filled, see Fig.
3.11 and Fig. 3.12.
Free inlet or outlet pipe section
Select the measuring point at a pipe section where the pipe cannot run empty, see Fig. 3.13 and Fig. 3.14.
3.4 Undisturbed flow profile
Some flow elements (e.g., elbows, valves, pumps, reducers) distort the flow profile in their vicinity. The axisymmetrical
flow profile in the pipe needed for correct measurement is no longer given. A careful selection of the measuring point helps
to reduce the impact of disturbance sources.
It is most important that the measuring point is chosen at a sufficient distance from any disturbance sources. Only then it
can be assumed that the flow profile in the pipe is fully developed. However, measuring results can be obtained even if the
recommended distance to disturbance sources cannot be met for practical reasons.
The recommended straight inlet and outlet pipe lengths for different types of flow disturbance sources are shown in the
examples in Tab. 3.1.
Fig. 3.9: Recommended transducer
mounting position Fig. 3.10: Disadvantageous transducer
mounting position
Fig. 3.11: Recommended transducer
mounting position Fig. 3.12: Disadvantageous transducer
mounting position
Fig. 3.13: Recommended transducer
mounting position Fig. 3.14: Disadvantageous transducer
mounting position