1,721,011 research outputs found
Metodo e sistema per la rilevazione da remoto della posizione di un dispositivo PIG all'interno di una condotta in pressione
No full textSi descrivono un metodo e un sistema per la
rilevazione da remoto della posizione di un dispositivo
pig (10) all’interno di una condotta (12) per il
trasporto di fluidi in pressione, come ad esempio
10 oleodotti e gasdotti di lunga distanza che hanno una
valenza strategica internazionale. Il metodo prevede la
strumentazione della condotta (12) con sensori di
pressione (14) a contatto con il fluido, posti in
corrispondenza di almeno uno dei due terminali (A, B)
15 della condotta (12), e la trasmissione ed elaborazione
dei segnali da parte di un’unità di controllo (16). La
funzione del sistema è quella di identificare e
localizzare, in tempo reale e in continuo, un
dispositivo pig (10) che si muove a intermittenza
20 all’interno della condotta (12), per esempio durante
operazioni di pulizia, monitoraggio, misura e controllo
non distruttivo
Metodo e sistema di monitoraggio continuo da remoto dell'integrità di condotte in pressione e delle proprietà dei fluidi trasportati
No full textMetodo, con relativo sistema,di monitoraggio continuo da remoto dell’integrità di condotte in pressione (104) e delle proprietà dei fluidi trasportati, impiegabile preferibilmente con gasdotti e oleodotti di lunga distanza, comprendente le seguenti fasi:
- installare lungo la condotta una pluralità di stazioni di misura (103) collegate a sensori vibroacustici (101) atti a misurare, in simultanea ed in continuo, segnali elastici in propagazione nelle pareti della condotta e segnali acustici in propagazione in detto fluido trasportato;
- sincronizzare con un riferimento temporale assoluto detti segnali misurati x(t) da dette differenti stazioni di misura (103);
- trasmettere in continuo detti segnali misurati x(t) e sincronizzati ad un’unità centrale (102) atta ad elaborarli in maniera multicanale;
- calcolare mediante detta unità centrale (102) una pluralità di funzioni di trasferimento H(f) atte a definire la propagazione vibroacustica in tratti di condotta (104) compresi tra stazioni di misura (103) consecutive utilizzando come segnali di analisi detti segnali misurati e sincronizzati x(t) e le relative trasformate di Fourier X(f);
- aggiornare in continuo dette funzioni di trasferimento H(f) utilizzando segnali acustici ed elastici generati da sorgenti passive (T) presenti nella condotta (104);
- filtrare i segnali acustici ed elastici rilevati dalle differenti stazioni di misura (103) con sottrazione del contributo relativo alle sorgenti passive (T);
- realizzare un modello equivalente descrittivo del sistema comprensivo di fluido trasportato, condotta e mezzo esterno che circonda la condotta stessa, utilizzando dette funzioni di trasferimento H(f) concatenate tra loro
METHOD AND SYSTEM FOR CONTINUOUS REMOTE MONITORING OF THE INTEGRITY OF PRESSURIZED PIPELINES AND PROPERTIES OF THE FLUIDS TRANSPORTED
No full textMethod, with relative system, for continuous remote monitoring of the integrity of pressurized pipelines (104) and properties of the fluids transported, preferably able to be used with long-distance gas pipelines and oil pipelines, comprising the following phases:
- installing a plurality of measurement stations (103) along the pipeline, connected to vibroacoustic sensors (101) suitable for simultaneously and continuously measuring elastic signals propagating in the walls of the pipeline, and acoustic signals propagating in said transported fluid;
- synchronizing said signals x(t) measured from said different measurement stations (103), with absolute time reference,;
- continuously transmitting said measured and synchronized signals x(t) to a central unit (102) suitable for processing them in a multichannel mode;
- calculating, by means of said central unit (102), a plurality of transfer functions H(f) suitable for defining the vibroacoustic propagation in sections of pipeline (104) between consecutive measurement stations (103) using, as analysis signals, said measured and synchronized signals x(t) and the relative Fourier transforms X(f);
- continuously updating said transfer functions H(f) using acoustic and elastic signals generated by passive sources (T) present along the pipeline (104);
- filtering the relevant acoustic and elastic signals from the different measurement stations (103) subtracting the contribution relating to the passive sources (T);
- creating an equivalent descriptive model of the system comprising the fluid transported, pipeline and external medium surrounding the pipeline itself, using said transfer functions H(f) connected with each other
METHOD AND SYSTEM FOR THE REMOTE DETECTION OF THE POSITION OF A PIG DEVICE INSIDE A PRESSURIZED PIPELINE
No full textA method and a system are described for the remote detection of the position of a pig device (10) inside a pipeline (12) for transporting pressurised fluids, like for example long distance oil and gas pipelines having a strategic international value. The method foresees equipping the pipeline (12) with pressure sensors (14) in contact with the fluid, located at at least one of the two terminals (A, B) of the pipeline (12), and the sending and processing of signals by means of a control unit (16). The operation of the system is that of identifying and locating, in real time and continuously, a pig device (10) that moves intermittently inside the pipeline (12), for example during cleaning, monitoring, measurement and non-destructive control operations
Pipeline acoustic monitoring
No full textMulti-point Acoustic Sensing (MAS) technology makes use of hydrophone sensors placed at discrete distances along pipelines in order to detect third party interference (TPI) and leaks. In fact, any interaction with the pipe generates pressure waves that are guided within the fluid for long distances, carrying information on the source event. Pressure propagation is mainly governed by the absorption coefficient and the sound speed. These parameters are in turn complicated functions of the frequency, the geometrical and elastic parameters of the pipe shell, the elastic parameters of the surrounding medium, and the acoustic and thermodynamic properties of the transported fluid.
We have designed several experimental campaigns on oil and gas transportation pipelines, instrumented with a proprietary MAS system. We have defined and simulated an exhaustive set of TPI and leak tests, taking care of the quantitative characterization of the dynamic parameters, especially at the source point. In this paper we describe the experimental work, and we discuss the data processing for the detection of pipe/flow anomalies. The results are also used for the validation of mathematical models of pressure waves propagation in fluid filled pipes
METODO E SISTEMA DI CALIBRAZIONE CINEMATICA PER LA MISURA DI SPOSTAMENTI E VIBRAZIONI DI OGGETTI/STRUTTURE
No full textMETODO E SISTEMA DI MONITORAGGIO DA REMOTO DEL CAMPO BI/TRIDIMENSIONALE DI SPOSTAMENTI E VIBRAZIONI DI OGGETTI/STRUTTURE
No full textVibroacoustic Monitoring of Gas-Filled Pipelines
No full textVibroacoustic monitoring is an emerging technique for the detection of leaks and third party interference (TPI) on fluid transportation pipelines. The technique is based on the remote identification of fluid transients and pipe shell vibrations produced by the interaction with the pipe and with the flow, and transmitted through the conduit. The system performance is a function of the thermodynamic properties of the fluids, that can be mainly separated in liquids, gases, and multiphase mixtures. While liquids are considered incompressible, gases and multiphase mixtures can sustain strong volume variations, thus producing variable flow regimes along the pipeline. We analyze here pressure transients propagation in gas filled pipelines. We have run field test campaigns in many scenarios, at different pressures, with and without flow, also in operational conditions, generating controlled interactions with the infrastructure and collecting vibroacoustic signals with a proprietary network of monitoring stations placed along the pipeline. We process the data in order to derive pressure transients propagation parameters and detection distance, to characterize the source wavelet with respect to the interference action (leak, impact, etc.), to analyze the effects of flow and turbulence, to validate mathematical models, and finally to design and calibrate advanced procedures for real time pipeline monitoring
Necrosis of the nipple-areola complex in breast reduction: our personal way to solve problem
No full textNecrosis of the NAC is a condition that penalizes patients who underwent breast reduction surgery or mastopexy. Breast
reduction is a widely used technique for over-sized breasts. Breast hypertrophy, in fact, can cause the onset of many
issues - both aesthetical and pathological - because of the excessive weight that the breasts exert on the patient’s spine.
Aim and objective of our study is to suggest a systematic use of diagnostic imaging composed of pre-operative and intraoperative
ultrasound with color-Doppler and pre-operative MRI.
Trying to solve this problem definitively, we relied on our notions of anatomy on ten fresh cadavers, on whose twenty
breasts we could make very detailed dissections. The dissections led us to conclude that, albeit with their anatomic differences,
each breast was characterized by a vascular-nervous pedicle coming out from the inter-costal spaces and aimed
to the blood supply to the NAC. To overcome the anatomic variations between one subject and another - but also
between one breast and the other from the same patient, we relied on diagnostic imaging, both in the pre-operative and
in the intra-operative staging. This way we were able to intervene successfully with 15 patients, none of which has complained
damages to the vascularity or innervation of the NAC so far. In conclusion we believe that pre and intra operative
diagnostic imaging is the only way to completely eliminate any potential risk of NAC necrosis. Only by means of
the systematic use of conventional imaging - especially during surgery - it is possible to constantly monitor the position
of the NAC’s pedicle in a breast that is being reduced in volume
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