Impact recording system to characterise centrifugal spreading

This paper presents a new method to measure simultaneously the horizontal and vertical distribution of the mass flow in the vicinity of the spinning disc of fertiliser centrifugal spreaders. The method consists in recording granule impacts on a cylindrical vertical screen placed around the disc. Algorithms have been developed to process the impact recording band taking into account its location with respect to the spreading device. The distribution of the mass flow has been studied for three fertilisers. Our findings show that the horizontal and vertical distributions of the mass flow are similar for ammonium nitrate and NPK, while they are different for KCl. For each fertiliser, the horizontal distributions deduced from impact records are in accordance with results deduced from a traditional compartmented ring. This new method is useful to study the vertical distribution of fertiliser granules and paves the way to design simple test and diagnostic tools.