Maciej Niedostatkiewicz

ECT Image Analysis Methods for Shear Zone Measurements during Silo Discharging Process

Abstract The paper covers the electrical capacitance tomography (ECT) data analysis on shear zones formed during silo discharging process. This is due to the ECT aptitude for detection of slight changes of material concentration. On the basis of ECT visualisations, wall-adjacent shear zone profiles are analysed for different wall roughness parameters. The analysis on changes of material concentration, based on ECT images, enables the calculation for the characteristic parameters of shear zones—size and material concentration inside the shear zone in a dynamic process of silo discharging. In order to verify the methodology a series of experiments on gravitational flow of bulk solids under various conditions were conducted with different initial granular material packing densities and silo wall roughness. The investigation shows that the increase in container wall roughness is an effective method for reducing the dynamic effects during the material discharging, since these effects are resulted from the resonance between hopper construction and trembling material. Such effects will damage industrial equipment in practical applications and need further investigation.

Application of twin-plane ECT sensor for identification of the internal imperfections inside concrete beams

The main purpose of this paper is to investigate application of special construction of Electrical Capacitance Tomography (ECT) sensor to concrete beams internal homogeneity tests. Identification of internal imperfection inside the concrete beams is one of the main problems related to analysis of the construction structure bearing capacity. Therefore, this paper shows attempts to study the measurement prospects for this non-invasive, tomography based technique, in regard of concrete construction elements structure investigation. Presented results come from experiments with two types of internal inclusions, which cause the non-continuity at the concrete structure: soft and hard (of density lower, and higher, than this of pure concrete beam). The positions and dimensions of the imperfections were sensed with two non-invasive methods; ECT and, in order to verify the outcomes, X-ray tomography imaging. The range of application and the accuracy of both methods, in aspect of measurement of material concentration changes inside concrete beams, are discussed here. For the purpose of measurement results interpretation, in case of ECT only capacitance, unprocessed measurement data were analyzed, since such raw data processing do not introduce additional soft-field effect inverse problem solution errors.