Relationship between mass flow and input torque of fertiliser broadcoaster spreading disc: modelling and experimental validation

Abstract

The aim of this work is to show that the driving torque of the spreading disc on a centrifugal broadcaster can be used as a fertiliser mass fl ow estimator. This fl ow estimation depends on physical properties of fertiliser and motion parameters on the spinning disc. Our study deals with the characterisation and the simulation of the resisting torque exerted by the fertiliser on the vanes. Several parameters are taken into account : location of the feeding point, speed of rotation, fertiliser features, disc shape, length and pitch angle of the vanes. Our model is validated by comparing calculated and measured values. Used on centrifugal spreaders, this mass fl ow estimation method can replace hopper weighing devices with some technical advantages (lower sensibility to accelerations, mass fl ow control on each spinning disc,...). As part of precision farming and site specifi c fertilisation, the use of the previous method allows effi cient real-time servo control system for the management of the fertiliser fl ow