ABSTRACT
A laboratory study was formulated to investigate the effect of spinning disc deterioration (damage of disc teeth and surface groove clogging) on the performance of ultra low volume sprayer. To do this, artificial teeth damages of varying degrees of severity were inflicted on three of five chosen identical spinning discs of 'Micron micro ulva' battery operated spinning disc ultra low volume sprayer. The fourth disc has its surface grooves artificially blocked and the fifth disc used as a control. Droplet samples were obtained from each of the differently treated discs and the control disc at random and measured using a particle size analyser. The Volume median diameters (Vmds), Number median diameters (Nmds), Dispersion- ratios (r), for each set of droplet samples were obtained. Also power consumptions for each of the discs when spraying were measured. There was found to be significant changes in droplet spectra with spinning disc deterioration, indicated by progressively higher values of volume median diameters, which is suggested to be attributed to the change of issuing points of droplets. There was, however, found to be no significant change in average droplet sizes (Nmds), but droplets were found to become less uniform with disc deterioration, indicated by higher values of dispersion ratios! (r). Power consumption was found to increase with disc damage, which would reflect on running costs of the machine, a factor which the user should be aware of.