Study of the Discharge and Heat Transfer Behavior of Granular Flow in a Silo(1/3)

Many materials in nature exist in the form of particles, such as gravel, stones, grains, and so on. The granular raw materials also can be found in the food industry, chemical industry, and pharmaceutical industry. Therefore these industries usually need to use silos, tanks, or hoppers for the storage of particles. The silo are used for the management of storage powder or particulate materials, and could control the discharge flow rate of the particles. For the size of the silo, it could be as large as the storage bins for storing cereals, feed and cement, and could be as small as the hourglasses. For the usage of silo, it can be sorted by long-term storage, short-term storage, re-stored and discharged, or filled into containers of the silo. However, the technique thresholds of the control of the discharge becomes harder for larger-scaled silo.This three-year project will study the granular discharge and heat transfer behavior in the silo. The first year of the project will investigate the discharge behavior of fine particles in a storage silo. Due to the discharge process of the storage silo is a two-phase flow, the influence of the interstitial fluid is very important. The interstitial fluid may usually accumulate in the storage silo to generate the bubbles. The flow behavior of the bubbles in the storage silo may affect the stability of the discharge process. The pressure variations inside the silo during the discharge process will also be studied in the first-year project. The second year of the project will conduct a series of analyses and investigations on the issue of heat transfer behavior of particles during the discharge process. The storage-silo-style heat exchanger is often be used in industrial applications. The second-year project will discuss the counter-current-storage-silo style heat exchanger, in which counter-current means that the flow direction of the granular discharge is opposite to the direction of the heating gas flow. The granular flow conditions in the silo also has a crucial influence on the overall heating effect, and it is also an important research issue. The third year of the project will discuss the effects of liquid on the granular material and the shape of the particles on the discharge behavior in the silo. Due to the relevant storage silo applications in the industry, there exists humidity in the material or the different shape of particles in the silo. The influence of the two effects above on the overall discharge process could not be ignored, and is also an important issue, and worth to investigate.