Chris Geijs – ESI/Eurosilo – Student werktuigbouwkunde 3 Onderzoek naar capaciteit en vermogen van transportschroeven in Eurosilo´s
Abstract
Eurosilos are used for large‐scale storage of bulk solid material. Research has been done to determine the transport capacity and the required energy flow for the transport augers used in these silos. A theoretical model has been developed for both the filling and reclaim process to relate the auger capacity to the required energy flow. Reclaim process The reclaim process consists of three separate processes. These processes determine the energy flow required for the digging auger. ‐ Digging into the bulk solid by the digging auger ‐ Transportation of the bulk solid material by the digging auger ‐ Displacement of the dam which consists of bulk solid The theoretical model produces realistic results for the reclaim process compared to measurements made in practice on existing coal silos in Helsinki. With known auger capacity, the model is able to make a good estimate of the required energy flow for the digging auger. The energy flows for the separate processes can be viewed and analyzed separately. The required energy flow for the transportation of bulk solid material turns out to be leading for the total required energy flow PL during the reclaim process. De required energy flow for digging into the bulk solid is relatively low, due to the equalizing auger, which loosens up the consolidated material (Paragraph 6.5.2 and 6.5.3). The required energy flow for dam displacement is relatively low with respect to the other separate processes. Filling process The filling process consists of two separate processes. The required energy flow for both augers can be determined with these processes. ‐ Transportation of the bulk solid by both augers ‐ Displacement of the dam by the digging auger The theoretical model produces realistic results for the filling process compared to measurements in practice to existing coal silos in Helsinki. Practice shows that the amount of transported bulk material isn’t equal for both augers. The theoretical model assumes equal transportation amounts for both augers during filling. As a result there are differences between practice and theory for the required energy flow. This must be taken into account when making an estimate of the required energy flow for both augers during the filling process.Chris Geijs – ESI/Eurosilo – Student werktuigbouwkunde 4 Onderzoek naar capaciteit en vermogen van transportschroeven in Eurosilo´s The required energy flow for the transportation of bulk solid turns out to be leading for the total required energy flow during the reclaim process. The required energy flow for dam displacement is relatively low with respect to the separate transportation process. The required energy flow will be at a maximum when both augers are totally filled with bulk material and the auger frame starts rotating to a new position. General Any person who uses the theoretical model must be constantly aware of the model’s dependency on the properties of the bulk solid material. This must be taken into account when making an estimate for the required energy flow for both augers during filling and reclaiming. Variation of bulk solid material parameters within the model can be a useful tool to investigate this dependency for known silo design. Measurements in silos with different bulk solid materials could validate the theoretical model for a wide range of import data.
