Measurement and control systems for an imaging electromagnetic flow meter

Electromagnetic flow metres based on the principles of Faraday's laws of induction have been used successfully in many industries. The conventional electromagnetic flow metre can measure the mean liquid velocity in axisymmetric single phase flows. However, in order to achieve velocity profile measurements in single phase flows with non-uniform velocity profiles, a novel imaging electromagnetic flow metre (IEF) has been developed which is described in this paper. The novel electromagnetic flow metre which is based on the ‘weight value’ theory to reconstruct velocity profiles is interfaced with a ‘Microrobotics VM1’ microcontroller as a stand-alone unit. The work undertaken in the paper demonstrates that an imaging electromagnetic flow metre for liquid velocity profile measurement is an instrument that is highly suited for control via a microcontroller

On-Line Monitoring of the Non-Asisymmetric Flow Profile with a Multi-Electrode Inductance Flowmeter

A modified filtered backprojection (FBP) algorithm based on a revised S-L filter functions is developed to monitor the velocity profile of nonaxisymmetric flow inside a circular pipe with a multielectrode inductance flowmeter. This algorithm is simpler than the singular value decomposition (SVD) and pseudoinverse-based algorithms and fast enough to be used in on-line monitoring of flow profile. To further improve its real-time performance, a simplified algorithm is also proposed. Three kinds of nonaxisymmetric flow profiles, i.e., profiles with a single peak, with double peaks and with one peak and one reflux are simulated to evaluate the performance of the proposed algorithms. The projection data are obtained by solving the governing electric field equation. With these data the velocity profile of the pipe flow can be reconstructed using the new algorithms. The reconstructed profiles have been compared with those obtained by using simple backprojection methods. Results obtained demonstrate that the algorithms can be used to monitor the velocity profile of nonaxisymmetric pipe flows