R.C. Waterfall

Abstract: Opportunities for the use of nonin-vasive tomographic sensor technology are described and reviewed critically. Imaging instru-ments based on electrical sensing methods are dis-cussed with respect to a number of process applications, including measurement of com-ponent concentration profiles, phase boundaries, component velocities and component mass flow rate. The use of low-noise electronic devices for process image sensing and the computationally intensive digital signal processing systems for image reconstruction are discussed. Limitations of current electronic techniques, particularly for future ultra high speed image reconstruction are revealed and directions for future progress are elu-cidated. 1 introduction Process tomography provides real-time cross-sectional images of the distribution of materials in a process. By analysing two suitably spaced images it will be possible to measure the direction and speed of material move-ment. Hence from this knowledge of material distribution and movement, internal modes of the process can be derived and used as an aid to optimising the design of the process. In Section 5 we will describe how this promises a substantial advance on present methods of process design which are based on input/output measurements, with only a limited amount of empirical or analytical informa-tion about the internal behaviour of the process. The process industry uses high capital cost plant which is often designed and operated on the basis of pas