This thesis focuses on the applicability of large-scale homogenization in mammoth silos. Mammoth silos are frequently used for the storage of both free flowing and cohesive materials up to volumes of 100,000 m3. For the upgrading of free flowing bulk materials blending piles can be used. However, to date, an upgrading facility for cohesive bulk material is not available. Adding the functionality of homogenization to a mammoth silo means that both free flowing and cohesive materials can be stored and homogenized under climatological controlled circumstances.
The competitiveness of homogenizing in mammoth silos versus blending piles depends on the achievable rate of homogenization and the required homogenization efficiency for successive processes. Investment costs and available space are also relevant factors: there is an increasing market for compact and indoor storage facilities in densely populated areas.
Experiments were set up to investigate the suitability of a screw conveyor for inclined or declined stacking and reclaiming (Chapter 8). The main objective of these experiments was to compare the performance of the screw in an inclined position with that of the screw in a horizontal position. In conventional mammoth silos the screw conveyor operates horizontally. The experiments showed that for stacking and reclaiming downward a screw conveyor can be used to implement the stacking and reclaiming methods with an inclined conveyor.
The results of the simulations should be interpreted qualitatively instead of quantitatively when assessing the homogenization effect. The homogenization effect depends strongly on the input properties and therefore no conclusions can be drawn for estimating the homogenization effect for a particular material without knowing the characteristics of the input property. Therefore, the input properties have to be determined separately for each single batch of material.
