Simulation of failure by rolling contact of a rotating drum in a petrochemical company

Abstract

The purpose of this research was to develop the simulation of rolling contact failure between the rim and roller of a rotating drum belonging to a petrochemical plant, in order to determine the failure rate and the factors that influence it. For this one, a methodology was established and applied in the NPK granules plant of the Morón Petrochemical Complex, specifically in the rotary dryer of said plant. In this equipment, superficial fatigue phenomena occur between the rim and the radial rollers, such as the appearance of cracks, which after a certain time need to be repaired in order to guarantee safe operation. The fatigue problem is common in rotating drums, which are mainly composed of a cylinder that rests between tires and rollers that rotate with each other, producing a rolling contact during their operation, and therefore, a cyclical contact stress. The estimation of the failure rate due to cracks whose origin is located below the surface of the rim in a rotating drum, was achieved by simulation by finite elements, by using ABAQUS, to determine the contact stresses; the use of the Smith Watson and Topper equation to estimate crack nucleation; Neuber's equation for stress correction and the general fracture mechanics equation, together with the N'Pugno equation, for crack propagation. Finally, it is concluded that the higher the contact stress, the higher the rolling contact failure rate. These contact stresses are increased by skewing of radial rollers during alignment and by rim-related problems such as wobble, sidewall wear, surface wear, and rim deformation.