Failure analysis of a rotary satellite kiln located in a cement production line

The work herein presented aims to analyse the existing failures in a rotary satellite kiln of a cement production line, more specifically, the last 32 m of the equipment, which is responsible for the abrupt forced cooling of the clinker (cement component) throughout satellite coolers. This device undergoes pronounced temperature variation and, consequently, is subjected to high thermal induced stresses which are superimposed, due to its large dimensions, to structure's deadweight and the influence of a reduced angular rotation speed. The main failures observed in the equipment were the existence of cracks along the circum-ferentially weld bead of the outside nozzle to the kiln ferrule and the cracking of the kiln ferrule near the openings that allow the clinker to exit into the satellite coolers. The solution proposed to mitigate these failures was the implementation of reinforcement collars around the critical noz-zles, in order to achieve a better local distribution of stresses. Through the numerical simulations carried out using the Finite Element Method, it was verified that the average value of the first principal stress without the reinforcement collars was about 176 MPa. In the simulation with the implementation of the reinforcement collars, this value decreased to 75 MPa (approximately 57% lower). This should increase the equipment's durability.