Success Case: Auditing and Structural Analysis of a Slag Car

Reading Time: 4 minutes

Introduction

The inspection and analysis are two very important tools when it comes to the promotion of the integrity of an asset. They can be used, for instance, to verify potential flaws in the project, unforeseen/unknown phenomena investigation and the supply of technical support for maintenance planning.

In order to further understand these methods applied, we are presenting here one of KOT Engenharia’s success stories. In this article you will read about the overall vision of the study, also considering information on the work development sequence, its identified non-conformities and KOT’s role in the correction of these issues.

To review the ground concepts of the Finite Elements Method (FEM) and Visual Inspection, you can follow the links below:

  1. For the layman: understand what are Finite Elements Method
  2. Visual inspection of structural assets

Structural audit of the slag car

KOT was responsible for inspecting a slag car of a steel mining company. The structural conditions were analyzed through visual auditing methods, penetrating liquid and dimensional analysis, with the objective of identifying non-conformities and suggesting the due measurements for the equipment to adapt to a safe operation.

The visual auditing was carried out in order to verify the overall condition of the equipment, aiming to find points of deformation and warps. At the same time the inspection of the main welded joints and the evaluation of potential profiles and deformed plates, alongside further modifications in the project. Besides that, several non-destructive tests were carried out with the objective of also assessing potential cracks in the structure and several unconformities were found. In the chassis, for instance, the points highlighted on Figure 1 were found.

Figure 1: Overall view of the chassis, with the identification of the identified points [1].

On point 01 there was a weld in which the team assessed the presence of a transversal crack on the rolling path of the slag car, which can be seen in detail on Figure 2. Said crack was observed on the coffin profile table that forms the chassis. 

Figure 2: Crack observed on the transition radius of the chassis [1].

On Figure 3 you can see the result of a penetrating liquid test, which highlights the discontinuity over the surface of the welding area.

Figure 3: Evidence of the penetrating liquid test [1].

After the inspection analysis, it was realized that, as the defects were distributed over all the main structures, the safe operation of the equipment was compromised. That confirmed, KOT carried out a structural analysis of the car aiming to identify the attention points in the structure and evaluating the potential causes for the issues observed.

Structural analysis of  slag car

Besides the non-conformities identified in the inspection, a model was created grounded on finite elements for the simulation, thus considering the operation conditions of the project, current field condition and the criterion of analysis described in the applicable rules. The study encompassed the static analysis, fatigue and buckling of the components of the slag car. The model and the simulation results can be seen on Figures 4 to 7.

Figure 4: Finite element model of a slag car [1].
Figure 5: Index of usage considering different contact regions [1].
Figure 6: Effect of the temperature rise over the structure of the support ring for the loading of the ladle condition [1].
Figure 7: Influence of the load of the pot-end at the end of tipping on the structure of the hook-spring working as a solid body [1].

Thus, Kot Engenharia identified the attention points, analyzed the results acquired in its simulations, and developed solutions which embrace the substitution of equipment parts. Finally, the study allowed for the suitability of the slag car for obtaining a safe operating cycle.

Get in touch with KOT’s specialists team!

KOT Engenharia’s Team

With over 27 years of history and various services provided with excellence in the international market, the company promotes the integrity of its clients’ assets and collaborates in solutions to engineering challenges. For this integrity, it uses tools for calculation, inspection, instrumentation and monitoring of structures and equipment.

References: 

[1] KOT Engenharia’s archives.

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