Showing papers on "Ultrasonic flow meter published in 2006"

The Flow Velocity Distribution from the Doppler Information on a Plane in Three-Dimensional Flow

Abstract: In order to observe and estimate the flow of fluid in three-dimensional space, the pulsed Doppler method has been used widely. However, the velocity information acquired is only the velocity component in the beam direction of the wave even if an observation plane is formed by beam scanning. Accordingly, it is difficult to know the velocity distribution in the observation plane in tree-dimensional flow. In this paper, the new idea for processing the velocity distribution in the beam direction on an observation plane for transposing to flux distribution (flow function method) has been introduced. Further, the flow in an observation domain is divided into two kinds of flows, viz., the base flow which indicates the directivity of the flow in the observation domain and the vortex which is considered a two-dimensional flow. By applying the theory of a stream function to the two-dimensional flow, and by using the physical feature of a streamline to the base flow, the velocity component v which intersects perpendicularly to the beam direction is estimated. The flow velocity distribution in a scanning plane (observation plane) can be known from these two components of velocity, viz., beam direction component u and perpendicular component to the beam direction v. The principle was explained by an example of the blood flow measurement in normal and abnormal heart chamber, by the ultrasonic Doppler method.

An apparatus and method for measuring a parameter of a multiphase flow

Abstract: An apparatus is provided that determines a characteristic of a multiphase fluid, such as an aerated oil and water fluid, flowing within a pipe. The apparatus includes a fluid flow meter, a water cut meter, and a density meter, wherein the density meter determines the density of the fluid flow to determine the gas volume (or void) fraction of the multiphase fluid flow. The output signal of each of the meters is provided to a multiphase flow model to provide a plurality of multiphase parameters, such as phase fraction, volumetric flow, mass flow of each of the phases of the multiphase mixture, optimized for various flow conditions. Each of the meters may be secured to the outer surface of the pipe using various means, such a clamping means.

Mass flow meter or controller with inclination sensor

Abstract: A thermal mass flow meter associated with an inclination sensor that detects an angle of inclination of at least one portion of a thermal mass flow sensor relative to at least one reference axis. Based upon the detected angle of inclination, the output signal of the mass flow meter that is indicative of the mass flow rate of fluid through the sensor may be compensated to account for any inaccuracies relating to the orientation in which the mass flow meter is installed. Inaccuracies for which compensation may be provided include thermal siphoning effects and fluid buoyancy effects. By compensating for such inaccuracies, the mass flow meter may be used in any orientation, and/or may be used in non-inertial (e.g., accelerating) environments. The flow meter may be used as a stand alone device, or incorporated in a thermal mass flow controller.

A Multi‐Path Ultrasonic Transit Time Flow Meter Using a Tomography Method for Gas Flow Velocity Profile Measurement

Abstract: A velocity profile is the distribution of velocities in the axial direction over a cross-section of circular pipe. In this study, a new ultrasonic flow meter with a modified multi-path configuration, namely, a tomographic ultrasonic flow meter is proposed for the measurement of the flow velocity profile. The flow meter consists of a set of transmitting transducers and a set of receiving transducers placed at different positions on the pipe surroundings. This configuration produces an ultrasonic path in various directions and positions for the flow detection. Transmitting transducers, in sequence, propagate the ultrasound wave to all receiving transducers, and the axial velocity in each ultrasonic path is measured. The average velocity is calculated by using the weighting method. Using the theoretical flow profiles, the tomographic ultrasonic flow meter is simulated in asymmetric flow and compared to both the diametrical and quadrature configurations. The filtered back projection method is employed to reconstruct a flow velocity profile. In the reconstruction process, the flow velocity obtained in each ultrasonic path is used as the projection data. An experiment is also performed in a circular pipe for measuring the air flow velocity profile, in order to validate the proposed flow meter.

Methods for determining transducer delay time and transducer separation in ultrasonic flow meters.

Abstract: Methods and related systems for determining transducer delay time and transducer separation in ultrasonic flow meters At least some of the illustrative embodiments are a method comprising measuring a delay time for a first transducer pair, measuring a total measured time for ultrasonic signals transmitted between a second transducer pair in an ultrasonic meter in which both the first and second transducer pairs are installed, calculating a parameter associated with the second transducer pair using the delay time of the first transducer pair and the total measured time for said second transducer pair

Ultrasonic Flowmeter

Abstract: The ultrasonic flow-meter made by the authors, measures the frequency shifts caused by the liquid flow, using two pairs of transducers mounted in a case attached to both ends of the pipe. In the original configuration the sound waves travel between the devices that are in line with the direction of the liquid flow. The speed of the signal traveling between the transducers increases or decreases with the direction of transmission and the velocity of the liquid being measured. The phase shift of received signals, caused by frequency shift is proportional to the liquid's velocity. The signals are processed with a microcontroller included on the embedded electronics board, the results being displayed on a LCD.

Ultrasonic measuring unit having integrated humidity analysis

Abstract: An ultrasonic measuring unit and a method for detecting ultrasonic signal run-times, in which the ultrasonic measuring unit has two ultrasonic transducers for coupling ultrasonic signals into a flowing medium. Analysis electronics are provided to be accommodated on or in a flow tube, in which a gaseous medium such as circulating air flows. A probe unit is accommodated in the flow tube, the probe unit being assigned a temperature probe having a flow around it, whose measured value is used for correcting a temperature signal detected by ultrasound.

Low power ultrasonic flow measurement

Abstract: There is described a method of ultrasonic flow measurement for measuring a flow speed of a fluid in a conduit, the method comprising: providing an ultrasonic flow meter comprising a microprocessor, a clock, and a pair of ultrasonic transducers operable to transmit signals through the fluid and to receive the transmitted signals; switching the ultrasonic flow meter from a passive state to an active state at time intervals measured by the clock, an amount of power used by the ultrasonic flow meter in the passive state being less than an amount of power used by the ultrasonic flow meter in the active state; performing an ultrasonic flow measurement cycle; and switching the ultrasonic flow meter from the active state to the passive state following completion of an ultrasonic flow measurement cycle. There is also described an ultrasonic flow meter for measuring a flow speed of a fluid in a conduit.

Method and ultrasonic meter system for determining pipe roughness

Abstract: A method and ultrasonic meter system for determining pipe roughness. At least some of the illustrative embodiments are ultrasonic meters comprising a spool piece, and a first transducer pair mechanically mounted to the spool piece. The ultrasonic meter is configured to determine diagnostic data based on acoustic signals transmitted between the first transducer pair. The ultrasonic meter is configured to determine changes in the roughness of a pipe mechanically coupled to the ultrasonic meter based on a trend of the diagnostic data (wherein the trend comprises a substantially constant value of about unity for both asymmetry and cross flow and a substantially changing value for profile factor).

Transducer housing for an ultrasonic fluid meter

Abstract: A transducer housing for an ultrasonic fluid meter. At least some of the illustrative embodiments a transducer housing comprising a housing having a proximal end, a distal end and an internal volume, the housing couples to a spoolpiece of an ultrasonic meter, and an acoustic matching layer that fluidly seals the distal end from the internal volume (wherein the housing accepts a piezoelectric element within the internal volume and proximate to the acoustic matching layer). The acoustic matching layer has an acoustic impedance between that of the piezoelectric element and a fluid within the ultrasonic meter.

Adaptive Pulse Repetition Frequency Technique for an Ultrasonic Transit-Time Gas Flowmeter for Hot Pulsating Gases

Abstract: A technique of using an adaptive pulse repetition frequency (PRF) to operate an ultrasonic contrapropagation transit-time gas flowmeter (UFM) is introduced. This adaptive PRF technique allows transient measurements of hot (up to 450 degC) and pulsating (up to 1.5 kHz) gas flows. Such conditions occur in the exhaust gas of a combustion engine. Here, a UFM with the widely used fixed PRF technique is not applicable, because the large gas temperature variations would prevent a reliable detection of ultrasonic pulse arrival times. Coherently reflected waves are generated within the gas because of the unavoidable acoustic impedance mismatch between the gas and the transducers, and, depending on the gas temperatures, these echoes overlap with the main signal. The adaptive PRF technique overcomes this problem and allows correct pulse detection over the whole temperature range required. The UFM utilizes special high-temperature-resistant capacitance ultrasonic transducers (CUTs) to meet the requirements in terms of operating temperature range and dynamic response. Results, which are obtained with a preliminary laboratory prototype, are presented for the exhaust gas mass flow rate in a otimes 50-mm pipe measured at gas temperatures of up to 450 degC and at PRFs of up to 5.5 kHz, which is an increase in frequency response of one order of magnitude in comparison to existing measurement systems

Wet gas metering using a differential pressure based flow meter with a sonar based flow meter

Abstract: A method and apparatus for measuring a parameter of a wet gas flow is provided, wherein the apparatus includes a differential pressure based flow meter configured to determine a first volumetric flow rate of the wet gas flow. Additionally, the apparatus includes a sonar based flow meter configured to determine a second volumetric flow rate of the wet gas flow. Furthermore, the apparatus includes a processing device communicated with at least one of the differential pressure base flow meter and the sonar based flow meter, wherein the processing device is configured to determine the parameter (e.g., wetness, volumetric gas flow rate, and volumetric liquid flow rate) of the wet gas flow using the first and second volumetric flow rates.

A method op construction for a low cost plastic ultrasonic water meter

Abstract: There is described an ultrasonic flow meter comprising a pipe having two ends, electronic circuitry, a first enclosure housing the electronic circuitry, a second enclosure housing the pipe, and a plurality of ultrasonic transducers attached to an external surface of the pipe in the second enclosure The first enclosure is watertight, whereas the second enclosure is not watertight The two ends of the pipe protrude from the second enclosure Each transducer is covered by a respective cap and sealed from water ingress Each transducer is connected to the electronic circuitry by a respective pair of wires

Ultrasonic flow meter with flow mixer

Abstract: The invention relates to an ultrasonic flow meter comprising a flow passage, an ultrasound transducer and a flow straightener for removing or diminishing flow disturbances such as swirls. The flow straightener comprises at least a first and a second straightening means being oppositely twisted along a flow direction with a given twisting angle. The measurement accuracy of a flow meter is improved by the presence of the flow straightener.

Meter Electronics and Methods for Determining a Liquid Flow Fraction in a Gas Flow Material

Abstract: Meter electronics (20) for determining a liquid flow fraction in a gas flow material flowing through a flow meter (5) is provided according to an embodiment of the invention The meter electronics (20) includes an interface (201) for receiving a first sensor signal and a second sensor signal from the flow meter (5) and a processing system (203) in communication with the interface (201) The processing system (203) is configured to receive the first and second sensor signals from the interface (201), determine a substantially instantaneous flow stream density of the gas flow material using the first sensor signal and the second sensor signal, compare the substantially instantaneous flow stream density to at least one of a predetermined gas density that is representative of a gas flow fraction of the gas flow material and a predetermined liquid density that is representative of a liquid flow fraction, and determine the liquid flow fraction from the comparison

Non-invasive sensing technique for measuring gas flow and temperature

Abstract: A non-invasive method for measuring the flow rate and temperature of a gas flowing through a gas passageway. An inventive ultrasound sensor assembly includes a housing having opposed first and second ultrasound transducers. The housing is attachable onto an outside surface of a gas passageway, such as a pipe, at an angle θ relative to a gas flow direction within the gas passageway. Ultrasonic signals are sent from the first ultrasound transducer to the second ultrasound transducer, and vice versa, through the gas flow. Gas flow velocity and gas temperature are determined with the measured transit times of these ultrasonic signals through the gas flow. This non-invasive method eliminates sensor degradation, and eliminates the need for separate flow and temperature sensors. It also reduces power and time requirements, thus reducing cost.

Method for testing a mass flow rate meter

Abstract: A method of testing a mass flow rate meter functioning on the Coriolis principle, in which an apparatus of the mass flow rate meter is subjected to a predetermined oscillation excitation and the associated oscillation response is recorded. Then the recorded oscillation response is compared with a previously recorded oscillation response. Testing of the Coriolis mass flow rate meter with regard, for example, to error tolerances in the manufacturing or with regard to a calibration condition is thereby enabled.

Crucial technologies of oil-transporting pipe leak detection and location based on wavelet and chaos

Abstract: By detecting pressure and flux simultaneously, the leak of an oil-transporting pipe can be found and diagnosed synthetically. The flux of pipes is measured by an ultrasonic flow meter; considering the precision of the flux measured, a method based on the character of intermittent chaos of the Duffing system to detect weak signals under strong noise is introduced. The ultrasonic signals with a certain frequency could be extracted accurately from the complicated strong noise. So the flux of pipes can be computed precisely by an accurate ultrasonic signal. The location of a leak position is mainly determined by the time difference between the negative pressure waves measured by the pressure sensors located at both ends of the oil-transporting pipe. A singular point of a negative pressure wave can be judged accurately by a coefficient feature of the local extreme values of the wavelet transform. So, the precise location of the leak position of the oil-transporting pipe can be found. It can be shown by results of experiments that the precision of the leak location has been improved effectively, which can be about 1%.

Fluid Flow Controller

Abstract: The present invention relates to a magnetic flow controller which transforms a slow reduction in pressure of fluid flow over time to a measurable fluid flow. Once a threshold pressure differential is reached, a flow passage through the flow controller opens rapidly to a relatively large opening, thereby generating a volume of fluid at high flux flowing through the passage, particularly to permit the measurement of the volume of fluid in a conventional flow meter. The device of the present invention integrates this low flux and transforms it to a measurable fluid flux, so that the fluid can be measured by the fluid meter within its optimum error range.This is accomplished while maintaining a pressure drop in the flow meter which is within the permitted standards. Thus, the invention provides relatively sharp shifts between substantially high flux flow and no flow, in a pulse-like manner.

Multiphase flow meter and data system

Abstract: A multiphase flow meter and data system (10) including a volumetric flow meter (20), a water percentage meter (30), a multiphase density sensor (100), and a data center (40) interconnected to the volumetric flow meter (20), the water percentage meter (30), and the multiphase density sensor (100). The multiphase density sensor (100) has piping with a first transition section, a non-conductive section, and a second transition section. Two conductive plates are externally mounted to the non-conductive section, thereby forming a capacitor. The multiphase flow meter and data system (10) provides a way to measure the percentages of water, gas, and/or crude oil that flow in a pipeline without the separation of phases on-line and in real time. The multiphase flow meter and data system (10) allows reliable real time measurement with the possibility to transmit results to a remote location without the presence of a technician at the measuring site.

3J-3 Reciprocal Operation of Ultrasonic Transducers: Experimental Results

Abstract: Ultrasonic transit-time flow-meters estimate fluid or gas flows from the difference in times of flight of upstream and downstream acoustic pulses. However, any delay differences arising from sources other than the flow to be measured will cause a troublesome "zero flow" offset error. In theory, the transducers used in the measurement system should not influence the zero flow error, as electroacoustic systems based on piezoelectric transducers have been shown to be reciprocal (when the media is stationary). However, care is required when designing the electrical interfaces for the piezoelectric transducers, if reciprocity in the system is to be utilized. This work presents technique and measurements that apply reciprocity to an ultrasonic transit-time flow-meter. Specialized electrical transducer interfaces with options to drive the transducers from either low or high impedance sources were used. Combined with a high-impedance receive mode these options made it possible to change the conditions for reciprocity in the system. We show reduced delay difference in 9 cases out of 10 when trying to utilize the reciprocal property compared to when we disregard it in favor for larger excitation energy. The delay improvements were accompanied by reduced differences between the center frequencies of the signals from the two paths

Ultrasonic flow meter system

Abstract: An ultrasonic flow meter system includes transducers arranged with respect to a conduit to define at least one chordal path through fluid flowing in the conduit, and at least one transmitting transducer and receiving transducer pair on the chordal path for generating a transit time signal. At least one receiving transducer is positioned to receive scattered energy to generate a range gated Doppler signal. The system further includes a processing subsystem for exciting the at least one transmitting transducer. The processing subsystem is responsive to the transit time signal and the range gated Doppler signal and configured to generate a velocity profile and a mean velocity of the fluid in the conduit.

Ultrasonic fluid-measuring apparatus

Abstract: PROBLEM TO BE SOLVED: To provide an ultrasonic fluid-measuring device capable of improving the measuring accuracy. SOLUTION: The ultrasonic fluid-measuring device 10 is equipped with an ultrasonic measuring section 20, having a first transducer 21 and a second transducer 22 in a measuring channel 14, and a first to fifth partition boards 25-29 arranged so as to be substantially parallel to an ultrasonic propagation route 24, connecting the first transducer 21 and the second transducer 22. A first to sixth flat channels 32-37 are formed, being laminated inside the measuring channel 14 through the use of the individual partition boards 25-29. In this measuring device 10, the first transducer 21 and the second transducer 22 are arranged so that the measuring section 20 measures the fluid velocity, in a flat channel decentered with respect to the center which lies along the laminating direction among the individual flat channels 32-37. COPYRIGHT: (C)2008,JPO&INPIT

Ultrasonic flow velocity meter and ultrasonic transducer thereof

Abstract: The invention provides an ultrasonic flow velocity meter that can measure the flow velocity of a fluid over a wide range of degree of contamination with high degree of accuracy The ultrasonic flow velocity meter includes a mounting base to be fixed to the outside of a conduit line in which the fluid to be measured flows, the mounting base having a mounting surface formed obliquely with respect to a longitudinal axis of the conduit line, a sending transducer fixed to the mounting base for emitting an ultrasonic wave to the interior of the fluid, a receiving transducer fixed to the mounting base and receiving the reflected ultrasonic wave having subjected to Doppler shift and emitted from the interior of the fluid, and a calculating unit for calculating the flow velocity of the fluid from the amount of the Doppler shift of the reflected wave received by the receiving transducer The sending transducer and the receiving transducer are being arranged so that an axis of sending and an axis of reception are coincided with respect to each other, continuously send the ultrasonic wave and continuously receive the ultrasonic wave, respectively