Analysis And Application For Silo Storage Pressure

A silo is a cylindrical structure for storing all kinds of granular materials and widely used in agriculture, mining, building materials industry, chemical industry, power industry and many other fields. In recent years, with the development of economic construction, more and more silos are built in china. In the silo design, the most critical step is to select the correct storage pressure. Nowadays, all of the storage pressure methods adopted in different countries are based on the Janssen theory. But there are lots of facts show that the Janssen equation ignored the influence of silo discharge. Therefore, to select the appropriate method to research in silos pressure is necessary.Many countries in the world have carried out theoretical analysis and experimental research on this problem and up to now, some conclusions have been obtained, though a lot of different points of view still exist.All the research of this paper is based on Wuhan Qingshan "7.9" silo accident and the aim is to analyze the storage pressure by using experimental research and numerical simulation. At the same time, all the results will be used to analyze the cause of the accident. The author has done some works as following:1. Thorough the model test, we obtain the lateral pressure distribution when the silo staic and discharge. By comparing with the code results, we found that the code results are less than the actual situation.2. A formula of lateral wall pressure is obtained based on the soil arching effect theory. The correctness of this formula is proved through model test.3. A discrete element model is established in the paper by using the software of PFC2d and obtains the numerical results. The influences of various Parameters are also considered in this paper.4. It is found that the granular arch cased by funnel flow is the main reason for pressure enlarge when silo discharge.5. The orifice diameter-particle size ratio is factors for silo discharge. When the orifice diameter-particle size ratio reach6.0, the silo will blockage in the paper. At the same time, the silo is easer to blockage when internal friction coefficient increase.6. By combining the discrete element simulation and finite element analysis, we can obtain accurate results for silo analysis. This method provides a new idea for the study of silos.