Abstract
Objectives/Scope
The objective of the current work is to study the erosion inside the air outlet header of a generic catofin reactors which are used to produce the propylene. During the regular maintenance cycle of these plants, it was found that at several places in the air outlet header region erosion and material removal were reported.
Methods, Procedures, Process
Erosion wear is the loss of material due to repeated impact of solid particles on a surface and causes major economic losses across diverse industries such as oil and gas, hydraulic transportation, and chemical processes. Erosion severely damages flow passages, valves and pipe fittings, leading to higher replacement costs as well as the loss of valuable production time. For example, some oil and gas fittings can fail after just 30 minutes of operation due to high erosion rates. Engineers need to quickly evaluate the erosion on dozens of design variations to find ways of stretching the part's lifespan in order to reduce costs and maximize process up-time. Erosion is a complex phenomenon that depends on many parameters. Particle parameters can include the following: Particle shape or angularity, particle size and erodent particle hardness. Flow parameters, on the other hand, have a stronger effect on erosion as it determines particle concentration, particle impact angle, and impact velocity. Other parameters affecting erosion are properties of target surface, i.e. surface hardness and multiphase effects Progress in understanding the erosion due to solid particles has been achieved by the use of computational fluid dynamics (CFD). CFD allows the accurate modelling of fluid flow and particle trajectory through pipelines and bends. Once the impact velocity and angle of the particles colliding against the surface are calculated, empirical correlations to quantify the erosion rate can be implemented. Computational Fluid Dynamics (CFD) methodology was used to understand the cause of material removal and further perform design iterations to come up with new design to reduce the erosion drastically.
Results, Observations, Conclusions
Many design iterations were performed in virtual environment by performing CFD simulations to understand the flow physics as well as impact of various parameters affecting erosion rate inside air outlet header. Each design modification and its impact on erosion rate is compared with base design to check the effectiveness of modification. Finally, with the help of simulation, three better designs were identified, which reduces the erosion drastically.
Novel/Additive Information
With the help of CFD simulation, one can test various design modifications as well as find a solution in less time and with less cost as compared to cost associated with inspections and repair.
Theoretical Equation of the Critical Impact Velocity in Solid Particles Impact Erosion
