No abstract

In process industries Coriolis mass flow meters (CMFs) are widely employed for measuring mass flows. Quite often, especially in the oil and gas (O&G) industry, owing to fluids with high viscosities, flow measurements may lie in low Reynolds number regions. At low Reynolds numbers (Re), a CMF reading may deviate under the influence of fluid-dynamic forces. With the help of extensive Fluid-Structure-Interaction simulations (FSI), a detailed insight into physical mechanisms leading to this deviation is provided. The main finding is that this deviation is a function of the Reynolds number and the effect can be explained by a periodic shear mechanism which interacts with the oscillatory Coriolisforce and reduces the tube deflection. Experimental results with and without a correction for this effect are shown and compared with corresponding numerical results. If the low Reynolds number effect were ignored, it would lead to errors as large as 0.5% to 1% at Re = 800, however by measuring the Re and making corrections, the effect is reduced to < 0.2%.

No abstract

The introduction of the Coriolis mass flow measuring principle was a milestone in instrumentation. By offering the most accurate direct mass flow measurement in situ, combined with the possibility of measuring density at the same time, it enabled customers in a variety of industries to profit from the most convenient metering even in challenging applications, where other measurement principles reached their limits. Alas the geometrical designs of the meters on the market seemed to have reached a natural barrier at 12" pipe diameters. However, the higher the masses flowing through the pipelines, the more important the lowest error of measurement possible becomes. In hydrocarbon measurement this is apparent. The paper presents the world's first commercial Coriolis mass flow meter with 4 tubes. The working principle is explained and the geometrical and physical advantages of the 4-tube design compared to existing 2-tube designs are highlighted. The paper also reflects on the mechanical construction of Coriolis mass flow meters in general and highlights the importance of a sophisticated mechanical concept.