An experimental investigation is carried out on the colliding behavior of acrylic particles in a cylindrical vessel agitated by a water jet. The water thus injected into the bath is circulated with a pump to keep the bath depth constant. The frequency of collisions is measured with a noise meter and a digital video camera. The diameter of the cylindrical vessel, the aspect ratio of the bath, the number of the particles, the diameter of the particles and water flow rate affected the frequency of collisions. An empirical equation is proposed for the frequency of collisions.
