Ultrasonic Flow Rate Measurement Research Articles

Wedge design for high-temperature ultrasonic flow rate measurement

Measuring flow of liquids in pipes is crucial for process control operations, including custody exchange, chemical manufacture and manufacture of foodstuffs. However, many of these processes are at elevated temperatures (up to 350 °C) where current commercially available ultrasonic systems are unable to operate or require shut-down of plant for flow-meter installation, such as with in-line, or wet, systems.Clamp-on ultrasonic flow meters are able to achieve flow measurements at high-temperatures, often with complex or heavy waveguides and stand-offs to keep the Pb(Zr,Ti)O3 (PZT) element away from the hot, process end, however with the introduction of commercially available high-temperature piezoelectric ceramics, this is starting to change.The final major design consideration is the ultrasonic wedge, which traditionally made from polymers or slower speed of sound materials, is not suitable for use above ∼200 °C. Presented here is a metallic wedge design, which offers a shear mode velocity closer to the longitudinal sound velocity of polymers but with exceptional temperature resistance offering a permanently installed flow monitoring solution for demanding industrial environments.A 1 MHz transducer with integrated 40-degree incident angle wedge in stainless steel exhibits a signal to noise of 29.3 dB in a Z mode path configuration, at temperatures up to 380 °C. This was shown to give a repeatable and stable flow rate measurement when connected to a commercial flow converter, on to a pipe containing mineral oil flowing at approximately 14.4 m3/hr.

SIMULATION AND ANALYSIS OF MICRO ELECTRO MECHANICAL SYSTEMS PIEZO CERAMIC TUBE FOR ULTRASONIC FLOW MEASUREMENT

Tube piezoceramic used for the laying of a variety of sensors with a relatively small diameter to the size of a few micrometer to a few milli meters. Materials used in Piezoceramic Tube specially formulated standards for cylinders, so many different kinds of sensors which has a cylindrical shape for use as a place Piezoceramic. Use of Piezoceramic Tube one to measure ultrasonic flow. In the ultrasonic flow rate measurement distinction is made between two different measurement principles, namely the Doppler effect and timing analysis wave. In both cases Piezoceramic transducer placed on the walls of the tube produces ultrasonic waves, which are then transmitted into the liquid diagonal to the direction of flow.

Gas ultrasonic flow rate measurement through genetic-ant colony optimization based on the ultrasonic pulse received signal model

For gas ultrasonic flowmeters, the signals received by ultrasonic sensors are susceptible to noise interference. If signals are mingled with noise, a large error in flow measurement can be caused by triggering mistakenly using the traditional double-threshold method. To solve this problem, genetic-ant colony optimization (GACO) based on the ultrasonic pulse received signal model is proposed. Furthermore, in consideration of the real-time performance of the flow measurement system, the improvement of processing only the first three cycles of the received signals rather than the whole signal is proposed. Simulation results show that the GACO algorithm has the best estimation accuracy and ant-noise ability compared with the genetic algorithm, ant colony optimization, double-threshold and enveloped zero-crossing. Local convergence doesn’t appear with the GACO algorithm until –10 dB. For the GACO algorithm, the converging accuracy and converging speed and the amount of computation are further improved when using the first three cycles (called GACO-3cycles). Experimental results involving actual received signals show that the accuracy of single-gas ultrasonic flow rate measurement can reach 0.5% with GACO-3 cycles, which is better than with the double-threshold method.

A study of ultrasonic propagation for ultrasonic flow rate measurement

For the purpose of accurate flow measurement, an automatic three-dimensional (3D) sound field measurement system has been developed, and an experimental study has been conducted on ultrasonic properties. By using this system, ultrasonic sound pressure distributions and radiation angles in water have been measured. According to Snell’s law, the ultrasonic transmission properties can be obtained on the basis of incidence angle, acoustic impedance, basic frequency of ultrasound, and material and thickness of the metallic plate. However, this law cannot be applied to certain cases where an ultrasonic incident wave passes through a metallic plate and turns into a longitudinal wave, a shear wave and a Lamb wave. Consequently, the ultrasonic propagation paths have been investigated experimentally at various angles of incidence. From the experiments, it was confirmed that the ultrasonic beam paths change with incidence angles. Hence, the most suitable incidence angle has been determined from the result of measurements. Velocity measurements using an ultrasonic velocity profiler were made at various incidence angles. The accuracy of measuring flow rates changed with the incidence angles. The optimal incidence angle determined from 3D field measurements was found to yield the most accurate flow rates.

1706 超音波流量計測法におけるマイクロバブルの適用性(1)(OS17-2 超音波を利用した流動場の計測,OS17 超音波を利用した流動場の計測,オーガナイズドセッション)

1706 超音波流量計測法におけるマイクロバブルの適用性(1)(OS17-2 超音波を利用した流動場の計測,OS17 超音波を利用した流動場の計測,オーガナイズドセッション)

Ultrasonic flow rate measurement of low speed non-isothermal flows

In this study, a performance evaluation of a non-intrusive ultrasonic flowmeter is carried out for slow, non-isothermal flows. The purpose of the study is to investigate the adequacy of the above meter for flow rate measurements in thermal convection loops. The flowmeter is found to be useful only for part of the range of interest.