Monitoring solids cycle times by a novel optical approach in a conical spouted bed

The most popular techniques in the literature for measuring solid cycle times are either complex or require using radioactive particles. Therefore, a new inexpensive, easy and not hazardous technique for measuring solid cycle times has been developed and validated in a conical spouted bed pilot plant. The technique is based on the colour difference between traced and non-traced bed particles. Thus, a system composed of four RGB high-speed cameras is used to record the bed surface. Subsequently, the video recordings are fed into an image processing algorithm written in Matlab that automatically detects the traced particles and calculates the cycle times. Runs have been conducted in systems differing in the draft tube aperture ratio and operating with a vigorous bed with a high and dense fountain. The results have been compared with those obtained by visually following a traced particle through the transparent wall of the contactor. The obtained results have proven that the proposed technique provides reliable and accurate results for the solid cycle times and their distribution without the efforts and risk involved when using the current available techniques.