Wire-mesh sensors
Wire-mesh sensors belong to flow imaging techniques and allow the investigation of multiphase flows with high spatial and temporal resolution. The wire-mesh sensor principle is based on a matrix-like arrangement of the measuring points. Two set of wire electrodes are stretched along a vessel or pipe having a small axial separation between them and being perpendicular to each other. This way, a mesh or a grid of electrodes is formed in the cross-section (see figure).
The transmitter electrodes are sequentially activated while all receiver electrodes are parallel sampled, in such a way, that an electrical property (conductivity or permittivity) of the fluid in each crossing point is evaluated. Based on those measurements the sensor is thus able to determine instantaneous fluid distribution across the cross-section, for instance, of a pipe. The following pictures show the three-dimensional representation of a slug flow and the results of the visualization of different flow regimes of a air-water vertical flow.
State of the art
For the investigation of liquid flows conductivity wire-mesh sensors were firstly developed. They determine the local conductivity of a liquid in the cross-section of an investigation volume. They are well suitable for the investigation of mixtures with one electrically conductive phase, as in the case of water/air or water/steam mixtures. Such sensors were employed in various applications and have been used world wide.
The field of application of conductivity wire-mesh sensors is, however, limited by the fact that at least one flow phase must have an electrical conductivity of κ > 0.5 μS/cm. For this reason the principle of the wire-mesh sensor was extended to applications with non-conducting fluids. Thus, the development and integration of electrical capacitance (or permittivity) measurements into the principle of the wire-mesh sensor was crucial. The so-called capacitance wire-mesh sensor is thus applicable also in flow problems with oil or other organic and electrically non-conducting liquids. Therefore this sensor opens a variety of new application fields, for example in chemical engineering and in the oil & gas industry.
Wire-mesh sensors can be manufactured depending on application requirements in diversity of different cross-section geometry and operating parameters. In the meean time wire-mesh sensors for high temperatures and pressures can be manufactured for environmental condition of up to 400 °C and 10 MPa. The associated electronic systems for signal generation and data acquisition achieve a maximum temporal resolution of 10,000 frames/second and are suitable for up to 128 x 128 electrodes. Wire-mesh sensor types, sizes and manufacturing technologies are as manifold as their applications. For data analysis and visualization of the aquired raw data, a multitude of algorithms have been implemented, e.g. for calculation of phase fraction distributions, void fraction profiles, bubble size distributions, velocity profiles etc. Those algorithms are bundled in our "Wire-Mesh Sensor Data Analysis FrameWork". The wire-mesh sensor measurement technique is commercially merchandised world-wide by the HZDR-Innovation GmbH
The current research in the field of wire-mesh sensor technology concentrates on the further development of an online measuring system for industrial application, the extension of the applications, e.g. towards three-phase media - even in the presence of highly conducting media, such as salt water but also for Ex-Zones. Moreover, the coupling of the high spatially resolved wire-mesh sensors with flow throughflow measurements, with the aim of a precise multiphase metering system, is on high interest. Furthermore, the principle of the wire-mesh sensor technique can also be used for spatially resolved temperature and velocity measurements (anemometry).
Selected publications
- Wiedemann, P.; de Assis Dias, F.; Trepte, M.; Schleicher, E.; Hampel, U.
Towards Real-Time Analysis of Gas-Liquid Pipe Flow: A Wire-Mesh Sensor for Industrial Applications
Sensors 23 (2023) 4067, [DOI: 10.3390/s23084067] - Wiedemann, P.; de Assis Dias, F.; Schleicher, E.; Hampel, U.
Temperature Compensation for Conductivity-Based Phase Fraction Measurements with Wire-Mesh Sensors in Gas-Liquid Flows of Dilute Aqueous Solutions
Sensors 20 (2020) 7114, [DOI: 10.3390/s20247114] - Wiedemann, P.; Döß, A.; Schleicher, E.; Hampel, U.
Fuzzy flow pattern identification in horizontal air-water two-phase flow based on wire-mesh sensor data
International Journal of Multiphase Flow 117 (2019) 153-162 [DOI: 10.1016/j.ijmultiphaseflow.2019.05.004] - Hoffmann, A.; Schleicher, E.; Keller, L.; Leon Alonso, J.; Pitz-Paal, R.
Application of a single wire-mesh sensor in a parabolic trough facility with direct steam generation
Solar Energy 159 (2018) 1016-1030 [DOI: 10.1016/j.solener.2017.09.041] - Kesana, N. R.; Parsi, M.; Vieira, R. E.; Azzopardi, B.; Schleicher, E.; Mclaury, B. S.; Shirazi, S. A.; Hampel, U.
Visualization of gas-liquid multiphase pseudo-slug flow using Wire-Mesh Sensor
Journal of Natural Gas Science and Engineering 46 (2017) 477-490 [DOI: 10.1016/j.jngse.2017.08.010] - Kipping, R.; Kryk, H.; Schleicher, E.; Gustke, M.; Hampel, U.
Application of wire-mesh sensor for the study of chemical species conversion in a bubble column during chemical absorption of carbon dioxide in sodium hydroxide
Chemical Engineering & Technology 40 (2017) 1425-1433 [DOI: 10.1002/ceat.201700005] - Kipping, R.; Brito, R.; Schleicher, E.; Hampel, U.
Developments for the application of the Wire-Mesh Sensor in industries
International Journal of Multiphase Flow 85 (2016) 86-95 [DOI: 10.1016/j.ijmultiphaseflow.2016.05.017] - Dos Santos, E. N.; Schleicher, E.; Reinecke, S.; Hampel, U.; Da Silva, M. J.
Quantitative cross-sectional measurement of solid concentration distribution in slurries using wire-mesh sensor
Measurement Science and Technology 27 (2016) 015301 [DOI: 10.1088/0957-0233/27/1/015301] - Parsi, M.; Vieira, R. E.; Torres, C. F.; Kesana, N. R.; Mclaury, B. S.; Shirazi, S. A.; Schleicher, E.; Hampel, U.
Experimental investigation of interfacial structures within churn flow using a dual wire-mesh sensor
International Journal of Multiphase Flow 73 (2015) 155-170 [DOI: 10.1016/j.ijmultiphaseflow.2015.03.019] - Vieira, R. E.; Parsi, M.; Mclaury, B. S.; Shirazi, S. A.; Torres, C. F.; Schleicher, E.; Hampel, U.
Experimental Characterization of Vertical Downward Two-Phase Annular Flows Using Wire-Mesh Sensor
Chemical Engineering Science 134 (2015) 324-339 [DOI: 10.1016/j.ces.2015.05.013] - Parsi, M.; Vieira, R. E.; Torres, C. F.; Kesana, N. R.; Mclaury, B. S.; Shirazi, S. A.; Schleicher, E.; Hampel, U.
On the effect of liquid viscosity on interfacial structures within churn flow: experimental study using Wire Mesh Sensor
Chemical Engineering Science 130 (2015) 221-238 [DOI: 10.1016/j.ces.2015.03.033] - Vieira, R. E.; Kesana, N. R.; Torres, C. F.; McLaury, B. S.; Shirazi, S. A.; Schleicher, E.; Hampel, U.
Experimental Investigation of Horizontal Gas–Liquid Stratified and Annular Flow Using Wire-Mesh Sensor
Journal of Fluids Engineering - Transactions of the ASME 136 (2014) FE-13-1571 [DOI: 10.1115/1.4027799] - Vieira, R. E.; Kesana, N. R.; Torres, C. F.; Mclaury, B. S.; Shirazi, S. A.; Schleicher, E.; Hampel, U.
Experimental Investigation of the Effect of 90 Degrees Standard Elbow on Horizontal Gas-Liquid Stratified and Annular Flow Characteristics using Dual Wire Mesh Sensors
Experimental Thermal and Fluid Science 59 (2014) 72-87 [DOI: 10.1016/j.expthermflusci.2014.08.001] - Vieira, R. E.; Kesana, N. R.; Torres, C. F.; Mclaury, B. S.; Shirazi, S. A.; Schleicher, E.; Hampel, U.
Experimental Investigation of Horizontal Gas-Liquid Stratified and Annular Flow using Wire Mesh Sensor
Journal of Fluids Engineering - Transactions of the ASME 136 (2014) 121301 [DOI: 10.1115/1.4027799] - Hampel, U.; Otahal, J.; Boden, S.; Beyer, M.; Schleicher, E.; Zimmermann, W.; Jícha, M.
Miniature conductivity wire mesh sensor for gas-liquid two-phase flow measurement
Flow Measurement and Instrumentation 20 (2009) 15-21 [DOI: 10.1016/j.flowmeasinst.2008.09.001] - Pietruske, H.; Prasser, H.-M.
Wire-mesh sensors for high-resolving two-phase flow studies at high pressures and temperatures
Flow Measurement and Instrumentation 18 (2007) 87-94 - Prasser, H.-M.; Krepper, E.; Lucas, D.
Evolution of the Two-Phase Flow in a Vertical Tube - Decomposition of Gas Fraction Profiles according to Bubble Size Classes using Wire-Mesh Sensors
International Journal of Thermal Sciences 41 (2002) 17-28. - Prasser, H.-M.; Böttger, A.; Zschau, J.
A New Electrode-Mesh Tomograph for Gas-Liquid Flows
Flow Measurement and Instrumentation 9 (1998) 111-119
Further publications about wire-mesh sensors.
Patents
- Schleicher, E.; Tschofen, M.; Pietruske, H.
Gittersensor-System zum Charakterisieren einer Fluidströmung
DE 102015117084, PCT/DE2016/100397 - Schleicher, E.; Löschau, M.; Van Campen, L.
Anordnung zur Bestimmung der Phasenverteilung in mehr-phasigen Medien mit mindestens einer hochleitfähigen Phase
DE102013203437; BR112015020248-9; CA 2,899,997; EP 14708229.1; RU 2015 132 223; US 14/771,070 - Schleicher, E.; Sühnel, T.; Boden, D.; Fischer, F.; Futterschneider, H.
Grid Sensor
DE 102007019926 (Gittersensor), US 000008159237 - Da Silva, M.J.; Schleicher, E.; Hampel, U.; Prasser, H.-M.
Grid sensor for the two-dimensional measurement of different components in the cross section of a multiphase flow
WO 2007 121708, DE 10 2006 019178, US000007940038 - Pietruske, H.; Sühnel, T.; Prasser, H.-M.
Grid sensor.
DE 10 2004 019739, WO 2006 114081