Experimental Characterisation of the Tangential and Cylindrical Fertiliser Distribution Pattern from a Spinning Disc: A Parameter Study

Traditionally the performance of centrifugal spreaders is evaluated in spreading halls by measuring fertiliser distribution patterns in standardised tests. Alternative distribution patterns can be measured with compact devices that intercept the particle flow immediately after leaving the spinning disc. An experimental facility was built which allowed the measurement of the tangential, as well as the cylindrical distribution of the particle flow at the disc edge. A number of experiments were carried out, using one type of centrifugal spreader with a conical disc. The influences of vane length, mass flow rate, particle size and fertiliser type on both the tangential and the cylindrical distribution patterns have been investigated. The results show that flows of particles with a larger mean diameter achieve a higher velocity on the disc, causing the distribution patterns to shift to lower angular positions. Furthermore, it is concluded that a smaller average particle size leads to a higher mass discharge flow rate from the hopper. In addition, a shift of the cylindrical distribution to a lower vertical position is observed when the mass flow rate increases.