Pressure measurements in a full-scale fly ash silo

SUMMARY In cooperation with the Danish electrical power supply organizations Elkraft and Elsam, test series have been carried out in a circular fly ash bin with a diameter of 16 m and a height of 28 m. The bin is emptied by an arrangement that causes sector-wise fluidizing inthe slightly inclined bottom. This silo has been equipped with 19 pressure cells to measure the total pressure, and the same number of pore pressure cells were made and mounted in accordance with theoretical and experimental results developed at the Department of Structural Engineering, Technical University of Denmark. An interpretation of the test results shows that two types of flow field can exist, depending on certain conditions: one with mass flow and an almost rotationally symmetric pressure distribution, and one with partial funnel flow and a non-uniform pressure distribution. During flow it has been observed that the flow field can suddenly change between these two types. Such changes have been found to be connected with a con...