Effect of working pressure, fluid temperature, nozzle type and nozzle orifice size, on spray characteristics using viscous feed additive DL-2-hydroxy-4-(methylthio)-butanoic-acid

Abstract Liquid ingredients in livestock feed are often added by spraying through commercial agricultural nozzles to a powdery matrix of mash feed. Homogenously distributing these ingredients is of utmost importance to achieve the required quality. This study aimed to evaluate the effect of working pressure, fluid temperature, and nozzle type and orifice size on droplet diameter distributions and spray area, which may influence liquid applications on feed. Optical diagnostics methods were used to study droplet size distributions and spray morphologies. DL-2-hydroxy-4-(methylthio)-butanoic acid, a common liquid additive, was chosen for this study. The spray droplet size distribution was coarser with conditions of low temperature and/or low pressure, while it was finer with high pressure and/or high temperature in a nonlinear way, sometimes giving bimodal distributions. The spray angle decreased strongly with temperature and/or pressure. Flat fan nozzles in this study produced sprays with greater maximum spray angle than the tested full cone nozzle but also with less regular droplet distributions. This work shows the effect that working parameters, and nozzle configuration have on spray morphology, particularly spray angle and volumetric droplet size distributions, and helps in the choice regarding these characteristics to improve spray applications for livestock feed manufacturing.