High temperature and high particulate density environments exist in the hopper, silo, gasifier, and combustor vessels used in advanced high efficiency coal-fired power plants. The surface and volume above a fluidized bed coal reactor contain a great deal of information about the conditions of combustion taking place within the fluidized combustion bed. The contour mapping system being developed will sense the condition of the bed surface using propagation of radio waves through the volume existing immediately above the combustion bed. This volume contains a distribution of gases and particles. The particles have a wide range of size, velocities, and distributions. In addition, the metal combustion vessel walls will create a multipath environment for the radio wave sensing signal. The paper summarizes research associated with the phased-array radar system being assembled for obtaining the surface contour of the contents in these vessels. Preliminary theoretical calculations from a simulated surface are presented. The phased array antenna system receives signals from both the near field and far field existing within the vessels.
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