An extractor for unloading the wet biomass stored in silo-bag

The storage of wet biomass can produce some problems when the biomass is emptied from silo-bags. Its extreme compactness and adhesion to the extractor cause clogging and product loss. Despite the importance of such an operation, the problem of silo-bag emptying has been addressed only rarely. This paper describes a new prototype of extractor designed for unloading the wet biomass from silo-bags. The machine was tested on silo-bags (of a capacity of around 200 t) filled with corn silage stored for two months. The study analyzed the qualitative parameters of the feedstock (density, moisture content, and particle size distribution), and the performance of the extractor in working conditions at three forward speeds (14.4, 18.0, and 21.6 m h−1). The extraction capacity of the machine proved comparable at the three speeds, but the maximum value (38.5 kg cm−1) was achieved at 18.0 m h−1. This speed, however, resulted in some clogging problems which caused a reduction in the working time (23.5%). Overall, the productivity proved satisfactory, ranging from 50.5 (at a forward speed of 14.4 m h−1) to 82.6 t h−1 (at a forward speed of 21.6 m h−1), while the material losses caused by the mechanical action of the extractor were low (0.09% w/w).