JOURNAL OF AGRICULTURAL SCIENCES, DEBRECEN, 2006/24. Basic Research for the Development of Fertiliser Spreaders

The knowledge of the physical characteristics of fertiliser particles is essential for the constructors and operators of fertiliser distributors. Among physical characteristics, the most important are the frictional and aerodynamic properties for the description of particle movement. Adjustable angled slopes, shearing boxes and various rotating disks are used to identify frictional properties. We have developed a high precision shearing box with digital force measuring cells and a distance signaller (incremental transducer) that we use for slide tests efficiently. We measured the frictional characteristics of 6 different fertilisers: the inner coefficient of friction and the coefficient of friction on ten test surfaces most commonly used in machinery, and we specified the relationship between displacement, loading and the coefficient of friction. We can conclude that the material of the frictional surface significantly influences the force of friction