Executive Summary : | In the present proposal conical spouted bed with draft tube will be studied. Experiment and Numerical investigation will be carried out for non-spherical particles. Various shapes of particle will be generated using multi-sphere methods for numerical studies. The spouted bed is majorly used in the industrial process where the material is susceptible to thermal treatment. The spouted bed offers better mixing and regular circulation of particles, as compared to traditional fluidized bed thus permitting the use of high-temperature fluid without the risk of thermal damage to solid particles. The hydrodynamics region for spouted bed can characterized into three regions: spout, fountain and annulus. Ordinary fluidized bed experiences an oscillatory, more random and more complex flow pattern, on the other hand, particles in the spouted bed move upwards through the spout and come down through the annulus. This particle circulation pattern is an advantage in drying/gasification processes to achieve a uniform heating. Hence, for applications involving particulate solids which are too coarse, non-spherical and uniform in size, spouted bed should be used. In the current study experiments will be carried out for Geldart Group D spherical particles, in a spouted bed. A spouted bed with conical shape base with draft tube and cylindrical column will be investigated. Pressure drop will be measured along the riser and will be measured by a pressure sensor. High speed camera and infrared camera along with thermocouples will be used to measure the hydrodynamics of bed fluidization and data will be generated to validate the simulation results. Detailed flow-field information cannot be obtained from experiments; hence numerical study will be done to understand the hydrodynamics and heat transfer characteristics between solid and fluid. A coupled Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) approach will be used to track solid-fluid interaction. Non-spherical particles will be modeled based on multi-sphere technique and soft collision model will be used to capture the inter collision of particles and with the bed walls. Novel design of draft tube based on spout shape will be studied for various non-spherical particles to achieve better mixing and fluidization. The development and understanding of close loop spouted bed with draft tube will pave the way to efficient and commercial use of fluidization in agriculture industry for drying of seed or gasification of biomass industry. Numerical algorithms developed in the current study can be used to study various spouted bed application areas connected to 3. Defense Food Research Laboratory (DFRL)-DRDO, India and large scale private industries like Thermax Ltd. India involved in clean and green energy. |