M. Divišová, D. Herák, A. Kabutey, V. Šleger, R. Sigalingging and T. Svatoňová
The deformation curve characteristics of rapeseeds and sunflower seeds compressed using the equipment ZDM 50-2313/56/18 and varying vessel diameters (40, 60, 80, and 100 mm) were investigated. Maximum compressive force of 100 kN was applied on bulk oilseeds of rape and sunflower of measured height 20-80 mm and deformed at a speed of 60 mm∙min-1. The compression test using the vessel diameters of 40 and 60 mm showed a serration effect while the vessel diameters of 80 and 100 mm indicated an increasing function effect on the force-deformation characteristic curves. Clearly, the increasing function effect described the region with oil flow and that of serration effect described the region without any oil flow. However, it was observed that the serration effect could be due to the higher compressive stress inside the smaller vessel diameters (40 and 60 mm) compared to those with bigger vessel diameters (80 and 100 mm). Parameters such as deformation, deformation energy, and energy density were determined from the force-deformation curves dependency showing both increasing function and serration effect. The findings of the study provide useful information for the determination of specific compressive force and energy requirements for extracting maximum oil from oilseed crops such as rape and sunflower.
A. Brunerová, M. Brožek, V. Šleger and A. Nováková
Production of briquette bio-fuel is related to several aspects of densification process. The present paper deals with the relation between briquette volume density ρ (kg·m−3) and required deformation energy Ed (J). Wood, energy crop and cardboard feedstocks were compressed by a laboratory briquetting press of two diameters (40 and 65 mm); in this way six kinds of briquette samples (W40, W65, E40, E65, C40, C65) were produced. The values of compressing force F (N) and briquette volume density ρ were measured directly during feedstock densification; the deformation energy Ed was calculated subsequently. The amount of deformation energy Ed consumed within the achievement of specific briquette volume density ρ levels differed in case of all samples, the same as the maximum achieved briquette volume density ρ levels. Best results, i.e. efficiency of briquette production (the highest ρ, the lowest Ed), were achieved by cardboard samples, followed by wood and finally by energy crop samples. An overall evaluation indicated a higher production efficiency of briquette samples 40 mm in diameter and the disadvantage of the production of briquette samples with briquette volume density ρ > 1000 kg·m−3; above such level, the amount of consumed deformation energy Ed increased disproportionately sharply.