This paper demonstrates the capability of an ultrasonic imaging system to visualize the interior of a flowing opaque solid-liquid slurry in real-time and to monitor its dynamically varying concentration distribution. This system provides a 100 mm × 100 mm viewing field of many flows of interest at a resolution that can discern detail smaller than 1 mm. In this paper, the results of visualization of a fluidized bed has been reported. The grayscale of the images were calibrated against a known solid fraction in the fluidized region. This was then used to characterize the solid fraction distribution in a more complex field with high concentration gradients and a full range of attainable solid fractions (～0 - 60%). It is shown that it is possible to penetrate suspensions even near maximum packing fractions at the given ultrasonic frequency of 5 MHz. The system has unique speed characteristics that lend themselves to situations where the solid distribution may change rapidly, acquiring images at a standard VHS video rate.
展开▼
