Variation of static pressure in a crambe (Crambe abyssinica Hochst) grains column

Abstract

The crambe has emerged as an option for the production of biodiesel, constituting itself as an alternative for off-season grain in Brazil. To obtain the best performance in the post-harvest product processing, knowledge of physical characteristics of the grains to as well as of the design of machines and structure storage is necessary. After pre-cleaning, the crambe (Crambe abyssinica Hochst) with a water content of 8% (wb) was placed into a silo prototype, provided a fan and plenum, and subjected to five airflow densities that were pre-determined in a total of four repetitions for each tested airflow. The static pressure was measured through the column in five layers. The results show that there is a significant effect of air flow on the static air pressure in the crambe column, which increased linearly with depth. The experimental data fitted with good accuracy the models of Hunter and Shedd, thus enabling their use for the crambe column as well. The objectives of this study were to evaluate the variation of static pressure along a column of grains of crambe that were subjected to five airflow densities and check the fit of this variation following mathematical models suggested by Sheed and Hunter.