Imaging a rectangular fluidised bed by electrical capacitance tomography: preliminary results

Abstract

Purpose

Rectangular fluidised beds are commonly used in industry, e.g. circulating fluidised bed (CFB) boilers. Apparently, no one has tried to imagine rectangular fluidised beds by electrical capacitance tomography (ECT). The purpose of this paper is to design a rectangular ECT sensor to understand the behaviour of a rectangular CFB riser.

Design/methodology/approach

A rectangular sensor with eight electrodes is adopted to obtain the capacitance data. The sensitivity map is simulated to calculate the grey level of pixels for visualisation using the linear back‐projection algorithm.

Findings

Experiments showed that the position of the objects in the riser can be obviously indicated and the central region of the object(s) has significantly higher grey level than other regions in the images using the rectangular ECT sensor.

Research limitations/implications

It has a limitation in providing a higher resolution image.

Practical implications

The results obtained by the rectangular ECT sensor show that it is promising to study the characteristics of flow non‐uniformity in the fast fluidisation regime of CFB.

Originality/value

Without using square and circular ECT sensors, this is the first time a rectangular ECT sensor has been developed to study the unique problems of the characteristics of flow non‐uniformity in a rectangular CFB riser.

Citation

Wang, W. and Yang, H. (2011), "Imaging a rectangular fluidised bed by electrical capacitance tomography: preliminary results", Sensor Review, Vol. 31 No. 4, pp. 315-320. https://doi.org/10.1108/02602281111169721