3-D imaging looks inside boilers

USA Today (Society for the Advancement of Education), June, 2006

A technique that records three-dimensional scans of the gases and solids that mix inside boilers and other industrial processing reactors has been invented by researchers at Ohio State University, Columbus. Scientists can use electrical capacitance volume tomography (ECVT) to observe how the density of materials varies inside a reactor. The end result could be better monitoring of reactor systems, including power plants.

Industrial plants need tomography for the same reasons hospitals do, explains L.S. Fan, professor of engineering. "Hospitals use tomography to view areas of the body that aren't easily or safely accessible, and the interiors of boilers and other high temperature reactors in industry are similarly inaccessible."

Fan studies the processes for converting coal to liquid fuels and chemicals in order to optimize the energy conversion efficiency while reducing power plant emissions. "Right now, the way to convert coal or natural gas to liquid fuels is in high-temperature, high-pressure reactors," he explains. "But if we're going to develop processes to achieve high-energy conversion efficiency, we need to be able to see inside those reactors to know how they work."

The invention includes a sensor system that measures the capacitance of the materials inside the reactor--their ability to store an electrical charge. Software then converts those measurements to information about the materials' composition.

Materials flow inside these hot reactors in complex ways. So, the key to making ECVT work is a visualization system that presents the rapidly changing data accurately in three dimensions. Other techniques produce less accurate, two-dimensional images.