Free jets spun from a prilling tower

A mathematical model of the dynamics of an inviscid liquid jet, subjected to both gravity and surface tension, which emerges from rotating drum is derived and analysed using asymptotic and computational methods. The trajectory and linear stability of this jet is determined. By use of the stability results, the break up length of the jet is calculated. Such jets arise in the manufacture of pellets (for example, of fertilizer or magnesium) using the prilling process. Here the drum would contain many thousands of holes, and the molten liquid would be pumped into the rotating drum. After the jet has broken up into droplets, these droplets solidify to form pellets. The jets in this prilling process are curved in space by both gravity and surface tension.