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Sergio Silvestri - One of the best experts on this subject based on the ideXlab platform.

  • Influence of the length of lead lines on the response of a variable Orifice Meter: analysis of sensitivity and settling time
    2018 IEEE International Symposium on Medical Measurements and Applications (MeMeA), 2018
    Co-Authors: Federica Montagna, Chiara Caciotti, Daniela Lo Presti, Emiliano Schena, Carlo Massaroni, Sergio Silvestri
    Abstract:

    Gas flow measurements are pivotal in several medical applications. For instance, mechanical ventilators and applications for respiratory monitoring need flowMeters with strict requirements: they must be accurate, with adequate dynamic response, high sensitivity (especially if used for neonatal purposes), and they must be almost insensitive to the composition of the gas Only few types of flowMeters are may be used in these applications. Among differential pressure flowMeters, characterized by good static and dynamic responses, variable area Orifice Meters (VAOMs) are gaining large acceptance in applications related to respiratory monitoring, estimation of respiratory function, and mechanical ventilation. VAOMs consist of two main parts: a primary element (basically a restriction), and a secondary element (i.e., a differential pressure transducer). The installation of the primary and the secondary elements can strongly influence the input-output relationship of VAOMs and can introduce relevant bias error. The aim of this study was twofold: i) the experimental assessment of the influence of the lead lines length (LL) on the calibration curve of a variable Orifice Meter; ii) the experimental analysis of the influence of LL on the step response of the flowMeter in terms of settling time. Results show that the value of LL influences both the static response and the step response: regarding the static response, the sensor sensitivity significantly decreases with LL (e.g., the sensitivity decreases from 5.3 Pa/L·min-1 to 4.0 Pa/L·min-1, when LL increases from 4 cm to 182 cm); concerning the step response, the flowMeter increases the settling time from approximately 20 ms up to 60 ms using LL values of 4 cm and 182 cm, respectively. The findings of this study can be useful to figure out the impact of the LL value on the sensor response; in addition may provide useful information to correct the sensor response if it is used in condition of installation different from the one used during the calibration.

  • MeMeA - Influence of the length of lead lines on the response of a variable Orifice Meter: analysis of sensitivity and settling time
    2018 IEEE International Symposium on Medical Measurements and Applications (MeMeA), 2018
    Co-Authors: Federica Montagna, Chiara Caciotti, Daniela Lo Presti, Emiliano Schena, Carlo Massaroni, Sergio Silvestri
    Abstract:

    Gas flow measurements are pivotal in several medical applications. For instance, mechanical ventilators and applications for respiratory monitoring need flowMeters with strict requirements: they must be accurate, with adequate dynamic response, high sensitivity (especially if used for neonatal purposes), and they must be almost insensitive to the composition of the gas Only few types of flowMeters are may be used in these applications. Among differential pressure flowMeters, characterized by good static and dynamic responses, variable area Orifice Meters (VAOMs) are gaining large acceptance in applications related to respiratory monitoring, estimation of respiratory function, and mechanical ventilation. VAOMs consist of two main parts: a primary element (basically a restriction), and a secondary element (i.e., a differential pressure transducer). The installation of the primary and the secondary elements can strongly influence the input-output relationship of VAOMs and can introduce relevant bias error. The aim of this study was twofold: i) the experimental assessment of the influence of the lead lines length (L L ) on the calibration curve of a variable Orifice Meter; ii) the experimental analysis of the influence of L L on the step response of the flowMeter in terms of settling time. Results show that the value of L L influences both the static response and the step response: regarding the static response, the sensor sensitivity significantly decreases with L L (e.g., the sensitivity decreases from 5.3 Pa/L·min-1 to 4.0 Pa/L·min-1, when L L increases from 4 cm to 182 cm); concerning the step response, the flowMeter increases the settling time from approximately 20 ms up to 60 ms using L L values of 4 cm and 182 cm, respectively. The findings of this study can be useful to figure out the impact of the L L value on the sensor response; in addition may provide useful information to correct the sensor response if it is used in condition of installation different from the one used during the calibration.

  • an Orifice Meter for bidirectional air flow measurements influence of gas thermo hygrometric content on static response and bidirectionality
    Flow Measurement and Instrumentation, 2013
    Co-Authors: Emiliano Schena, Stefano Cecchini, Sergio Silvestri
    Abstract:

    Abstract This paper presents the design and calibration of an ISO non-compliant Orifice plate flowMeter whose intended use is for respiratory function measurements in the bidirectional air flow range ±9 L/min. The novelty of the proposed sensor consists of a plate beveled in both upstream and downstream sides: a symmetrical geometry is adopted in order to perform bidirectional measurements of flow rate. A mathematical model is introduced to quantify the influence of temperature on the sensor output. Four different positions of the pressure static taps are evaluated in order to maximize bidirectionality. An index is also introduced in order to quantitatively estimate the anti-symmetry of the sensor's response curve. Trials are carried out to evaluate the influence on sensor output of air temperatures (22 °C, 30 °C and 37 °C) at different values of relative humidity (5%, 55% and 85%). Experimental data show a quite good agreement with the theoretical model ( R 2 >0.98 in each condition). The influence of air temperature on the sensor output is minimized by introducing a correction factor based on the theoretical model leading to measurement repeatability better than 2% in overall range of calibration. The mean sensitivity in the calibration range is about 2 kPa L −1 ·min allowing to obtain a sensor discrimination threshold lower than 0.2 L/min in both directions. The time constant of the whole measurement system, equal to 2.40±0.03 ms, leads to a bandwidth up to 80 Hz making the sensor suitable for respiratory function measurements.

O Buker - One of the best experts on this subject based on the ideXlab platform.

J Rabone - One of the best experts on this subject based on the ideXlab platform.

Mostafa Barigou - One of the best experts on this subject based on the ideXlab platform.

  • a comparative study of two flow conditioners and their efficacy to reduce asymmetric swirling flow effects on Orifice Meter performance
    Chemical Engineering Research & Design, 1999
    Co-Authors: A K Ouazzane, Mostafa Barigou
    Abstract:

    The sensitivity of differential-pressure flow Meters to the quality of the approaching flow continues to be a cause for concern to flowMeter manufacturers and users. Distortions to the approaching velocity profile generated by pipe fittings and installations located upstream of a flowMeter, can lead to considerable errors in flowMetering. This cannot be ignored because of the likely cost and process efficiency implications. This paper describes the effects of various entrance flow velocity profiles on the performance of an Orifice flowMeter with and without flow conditioning. Asymmetric swirling velocity profiles were generated by a ball valve. These caused significant shifts to the Meter's calibration. The use of a vaned-plate flow conditioner, consisting of six vanes attached to a 70% porosity plate, greatly improved the performance of the Meter. Thus, the device can be used as part of a flowMetering package that will have considerably reduced installation lengths. The less sophisticated NEL plate proved to be a good flow straightener, i.e. a good swirl remover, but was not an efficient flow conditioner.

T.b. Morrow - One of the best experts on this subject based on the ideXlab platform.

  • Metering Research Facility Program: Orifice Meter installation effects bibliography. Topical report, January 1995-May 1996
    1996
    Co-Authors: T.b. Morrow, P.j. Lanasa
    Abstract:

    This bibliography was developed to assist the ongoing activites of the American Petroleum Institute (API) Manual of Petroleum Measurement Standards Chapter 14.3, Part 2 working group for revision of the standard on Orifice Metering of natural gas and other hydrocarbon fluids. The chapter is concerned with specification and installation requirements for the design and operation of Metering facilities using Orifice Meters. The Orifice Meter Specifications section of the bibliography lists materials on the specification of Orifice plates, flanges, and fittings; sensing taps; Meter tubes; and flow conditioners.

  • Improved flow conditioners for Orifice Metering
    1995
    Co-Authors: T.b. Morrow, J. G. Gregor, R. S. Norman
    Abstract:

    A comprehensive research program on Orifice Meter performance is ongoing at the Gas Research Institute (GRI) Metering Research Facility (MRF). The objective is to determine the flow conditioning specifications necessary for acceptable Orifice Metering performance in installations built to conform with existing standards. Previous research results focused on conventional tube-bundle flow conditioners or straighteners in piping configurations that are typical of field installations. While this has resulted in recommandations for better use of tube-bundle flow conditioners for Orifice Metering applications, their proper use is contingent on paraMeters such as the flow Reynolds number, Orifice beta (β) ratio, pressure tap orientation, and inlet piping configuration. Therefore, the GRI program and other international flow research organizations are rigorously pursuing the test and development of alternate flow conditioners. This paper presents recent MRF results on the performance of flow conditioners used to minimize flow rate measurements errors in field installations of Orifice Meters.

  • Orifice Meter installation effects: Measurements of axial mean velocity, turbulence intensity, and swirl profiles upstream of the Meter tube installation. GRI Metering Research Facility Program. Technical memo
    1992
    Co-Authors: J.t. Park, T.b. Morrow
    Abstract:

    The test series described in this memorandum is part of the Metering Research Facility Orifice Meter Upstream Effects Research Program, conducted to investigate the benefit and feasibility of fitting flow conditioning devices into new gas flow Metering installations as well as retrofitting these devices into existing installations to assure proper upstream flow conditions. This report describes the Orifice Meter installation and documents the measured values. Because of the conclusions reached as a result of this test series, it is recommended that future Orifice Meter or turbine Meter installation effects tests use a 19-tube conditioner at the exit of the stagnation bottle.

  • determination of installation effects for a 100 mm Orifice Meter using a sliding vane technique
    Flow Measurement and Instrumentation, 1991
    Co-Authors: T.b. Morrow, J.t. Park, R J Mckee
    Abstract:

    Abstract As part of the Gas Research Institute Metering Research Facility Upstream Effects programme, a sliding vane technique is used to investigate the effects of straightening vane location on Orifice discharge coefficient and velocity profile in a D = 102 mm Orifice Meter installation. A standard ‘concentric pattern‘ 19 tube bundle straightening vane with a length to Meter tube diaMeter ratio of 2.5 was modified so that the distance, x, from straightening vane to Orifice plate could be changed rapidly without reassembling the Meter tube. This paper describes sliding vane experiments made with nitrogen gas at a pressure of 724 kPa (105 psi) in 45D and 19.5D long Meter tubes downstream of a single 90° elbow at a Reynolds number of 8.8 × 10 5 . Results are presented for the variation of Orifice discharge coefficient for β = 0.75 as a function of sliding vane location from x/D = 5 to 42.5. Complementary results are presented for the axial velocity profile distribution measured at the Orifice location in vertical and horizontal planes of the 45D Meter tube by hot-film anemoMeter at x/D values of 5, 11, 21, 39 and 42.5.