Acta Univ. Agric. Silvic. Mendelianae Brun. 2016, 64(5), 1593-1601 | DOI: 10.11118/actaun201664051593

Evaluation of Mechanical Parameters of Pellets

Ľubomír Kubík¹, František Adamovský², Viera Kažimírová³

¹ Department of Physics, Faculty of Engineering, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic

² Department of Electrical Engineering, Automation and Informatics, Faculty of Engineering, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic

³ Department of Production Engineering, Faculty of Engineering, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic

The paper dealt with the evaluation of mechanical properties of the cylinder wheat straw, rapeseed straw and 50/50 % mixed wheat and rapeseed straw pellet samples. The pellets were made by the granulating machine MGL 200 (Kovonovak). The compressive loading curves of dependencies of stress on strain were realised by the test stand Andilog Stentor 1000 (Andilog Technologies, Vitrolles, France). Certain mechanical parameters were determined, namely the initial force (force at 10 % of compress strain), force in maximum of loading curve, strain in maximum of loading curve, initial stress (stress at 10 % of compression strain), stress in maximum of loading curve and modulus of elasticity. Mean value of the initial force was maximal for mixed straw pellet samples 52.49 N. Mean values of the initial force of the wheat straw samples and the rapeseed straw samples were smaller and almost identical 43.58 N and 43.12 N. Mean values of the initial stress of loading curve, of the wheat straw samples reached 1.46 MPa, the rapeseed straw samples reached value 1.40 MPa and the mixed straw samples reached value 1.63 MPa. Mean value of the force in maximum of loading curve was also maximal for mixed straw pellet samples 213.26 N. Mean values of the force in maximum of loading curve of the wheat straw samples reached 178.11 N. The rapeseed straw samples reached value 95.95 N and the mixed straw samples reached value 213.26 N. Mean values of the stress in maximum of loading curve, of the wheat straw samples reached 5.93 MPa, the rapeseed straw samples reached value 3.11 MPa and the mixed straw samples reached value 7.10 MPa Mean values of the modulus of elasticity, of the wheat straw samples reached 18.27 MPa, the rapeseed straw samples reached value 13.08 MPa and the mixed straw samples reached value 14.97 MPa. Significant correlations of the mechanical parameters pellet samples were observed among initial force and initial stress and modulus of elasticity. Significant correlations of force in maximum with stress and strain in the maximum were observed.

Keywords: pellet, compress loading, mechanical properties

Grants and funding:

The research leading to these results has received funding from the European Community under project no 26220220180: Building Research Centre "AgroBioTech". Author express the appreciations of the Scientific Grant Agency of the Ministry of Education of Slovak Republic and the Slovak Academy of Sciences within the framework of the research were realized in the project Physical properties of biomaterials and the application of physical methods at the evaluation of the specific quality indicators of agricultural materials, No. 1/085400/14.

Prepublished online: October 31, 2016; Published: November 1, 2016  Show citation