Iris Trindade Chacon, Rodrigo Vivarelli Poggi Leal
METROLOGICAL EVALUATION OF FLOW MEASUREMENT SYSTEM APPLIED TO ONITORING BEER PRODUCTION

The present paper intend to present the main metrological aspects involved in the flow measurement system (SMV) applied to monitoring beer production. The installation of the SMV in the manufacture units appeared as a necessity of the Inland Revenue of Brazil (RFB) in inspect the quantity of beer produced, having as intention the attainment of reference elements that could supply comparison information with the taxed quantity. In this context, the intention is the combat to the tax evasion, especially the guarantee of the fair competition, based on the relevance of this segment for the Brazilian economy...

Gerald Steiner, Frank Podd
A NON-INVASIVE AND NON-INTRUSIVE ULTRASONIC TRANSDUCER ARRAY FOR PROCESS TOMOGRAPHY3

Ultrasound process tomography is a method for imaging the acoustic impedance or sound velocity distribution within a closed pipe or vessel. It can be used for the determination of process parameters in industrial multiphase flows. A crucial part of the imaging system is the ultrasonic transducer array. It influences the achievable accuracy as well as the possible application areas. Existing approaches are either invasive, where the transducers are in direct contact with the flow media, or intrusive, where the transducers extend into the flow. To overcome these drawbacks, we present the design of a novel non-intrusive and non-invasive ultrasonic transducer array. Important design parameters are discussed and analyzed using simulations. A prototype transducer arrays is introduced and the feasibility of ultrasound process tomography using a non-invasive and non-intrusive sensor front-end is verified with measurements.

Will Almeida, Bruno Costa, Raimundo Freire, Francisco Santos, Sebastian Catunda
UNCERTAINTIES PROPAGATION STUDY OF THE TRANSIT TIME METHODS IN ULTRASONIC ANEMOMETERS

The fluids speed measurement, particularly the air speed measurement is very important for industrial and laboratory applications. The ultrasonic method is among the most common methods used for determining the air speed. The basic principle to measure a fluid speed, using an ultrasonic transducer, is based on the modification of the apparent propagation speed of an ultrasonic signal caused by the fluid movement. Particularly, the method based on the Transit Time, which can use the techniques of Phase Difference and Time Difference, is one of the most used. In this work we carry on a comparative study of the uncertainty propagation employing these techniques in ultrasonic anemometers for determining the air speed.

Yaoying Lin, Volker Hans
IMPROVEMENT OF ULTRASONIC CROSS-CORRELATION MEASUREMENT OF GAS FLOW BY BLUFF BODY GENERATED VORTICES

Ultrasonic cross-correlation flow meters using natural turbulences in a fluid must be calibrated. The reason is that the most frequent components in the fluid are determined by this method deviating from the average flow velocity. The calibration characteristic is nonlinear and depends on the flow velocity and profile, respectively. This disadvantage can be avoided by small artificially generated vortices combined with cross-correlation measurement. In this case the vortices are travelling with average flow velocity. The detection of travelling time of a group of vortices between two ultrasonic barriers by cross correlation admits the direct determination of the average flow velocity. Furthermore, the combination of vortex and correlation measurement results in a self-monitoring system.

Xie Dailiang, Liang Guowei, Wang Fang
A MULTI-LOOP SENSOR FOR THE FLOWRATE MEASUREMENT OF GAS-LIQUID TWO-PHASE FLOW

A multi-loop flowmeter is designed for the flowrate measurement of the gas-liquid two-phase flow. The differential pressure signals can be collected from the multiloop sensor at different positions. The total flowrate measurement model is established according to the average differential pressure value obtained from the optimal position. The time serial of the signals is obtained by using the high speed data capture device. A non-dimensional characteristic value related to the root-mean-square of the dynamical differential pressure signals is obtained. The relationship between this value and the volume void fraction is established. The online measurement of the volumetric void fraction of gas-liquid two-phase is realized and the flowrate of the gas phase and the liquid phase are measured. The experiments showed that the results were satifactory.