Noninvasive locally and temporarily resolved measurement of sound velocity for process monitoring

用于过程监控的无创局部和临时解析声速测量

• 批准号: 239880265
• 负责人: Professorin Dr. Elfgard Kühnicke
• 金额: --
• 依托单位: Juniorprofessur für Mess-, Sensor- und Eingebettete Systeme (MSE Lab)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/239880265?language=en
• 关键词: Noninvasive; locally; temporarily; resolved; measurement

In times of increasing scarcity of resources, a detailed understanding and monitoring of technical processes is becoming increasingly important. Of particular interest are mixing processes in metallurgy, crystal growth and electrochemistry, which are - for example - needed for steel production or the production of silicon wafers. Information about the mixing process can be obtained by measuring the concentration of the different components as a function of time and location. Non-invasive measurement techniques allowing a combined determination of concentration with temporal and local resolution are currently unknown or solely work under strong confinements in transparent fluids. Therefore, the aim of the research project is to develop a completely new method for the monitoring of mixing processes by measuring the temporarily and locally resolved sound velocity using ultrasound. With the knowledge of the speed of sound at each measuring point, the corresponding concentration can be determined. The proposer achieved for the first time to measure the sound velocity in a fluid with moving scattering particles using a single ultrasonic transducer without the use of a reflector at a known position (back wall echo). The method uses the focus position, which depends on the sound velocity, as a second piece of information besides the time of flight. The focus position can be measured indirectly by determining the time of flight corresponding to the maximum of the echo signal maximum. The maximum position of the echo signal amplitude, in turn, indicates the time of flight to the focus, because the strongest echo signal is generated in the sound field maximum. By using simulated (or measured) calibration curves, the time of flight suffices to determine the sound velocity and the location of the ultrasonic focus in combination. This is the basis for the development of a novel measurement method. In the underlying project, ultrasonic arrays are used. The array elements are excited with slight time delays to move the focus position along the acoustic axis. This allows a locally and temporarily resolved measurement of sound velocity. The method is intended to be used for a vast variety of fluids including fluids with strong attenuation and scattering particles of different sizes and concentrations. Measurements during the mixing process of two liquids are intended for proof of concept. However, a much larger potential of applications can be expected. So, for example, chemical reactions can be monitored or temperature distributions can be determined. Thus, the new method can also be applied in the chemical and thermal process engineering, biochemical engineering or in food technology.

在资源日益稀缺的时代，对技术流程的详细了解和监控变得越来越重要。特别令人感兴趣的是冶金、晶体生长和电化学中的混合过程，例如，钢铁生产或硅片生产所需的混合过程。关于混合过程的信息可以通过测量作为时间和位置的函数的不同组分的浓度来获得。非侵入性测量技术，允许与时间和局部分辨率的组合确定的浓度是目前未知的或仅在透明流体中的强约束下工作。因此，该研究项目的目的是开发一种全新的方法，通过使用超声波测量暂时和局部分辨的声速来监测混合过程。通过了解每个测量点的声速，可以确定相应的浓度。提出者首次实现了使用单个超声换能器测量具有移动散射颗粒的流体中的声速，而无需在已知位置使用反射器（后壁回波）。该方法使用取决于声速的焦点位置作为除了飞行时间之外的第二条信息。可以通过确定对应于回波信号最大值的最大值的飞行时间来间接测量焦点位置。回波信号幅度的最大位置又指示到焦点的飞行时间，因为最强的回波信号在声场最大值中生成。通过使用模拟（或测量）校准曲线，飞行时间足以确定声速和超声焦点的组合位置。这是开发新型测量方法的基础。在基础项目中，使用了超声波阵列。阵列元件以微小的时间延迟被激励以沿着声轴沿着移动聚焦位置。这允许声速的局部和暂时分辨的测量。该方法旨在用于各种各样的流体，包括具有强衰减和散射不同尺寸和浓度的颗粒的流体。在两种液体的混合过程中进行的测量旨在验证概念。然而，可以预期更大的应用潜力。因此，例如，可以监测化学反应或确定温度分布。因此，新方法也可应用于化学和热过程工程、生物化学工程或食品工艺。