Modelling the influence of air jet configuration on non-woven steel fibre mixing in the melt overflow process

The mixing of non-woven steel fibres in melt overflow process for use in automotive muffler systems were simulated. The aim was to identify optimum parameters for achieving a good fibre mix. Numerical models of mixing chambers of melt overflow process were developed. Multiphysics analyses involving heat transfer, fluid flow and particle tracking were carried out using COMSOL software. The influence of air jet configurations on the fibre distribution were studied. The fibres settled on the moving bed within the mixing chamber were examined for their uniformity. The effect of additional air jets to the existing chamber in a range of regions was explored. An effective configuration was identified by analysing the compactness of the particle clusters deposited. The optimum air jet parameters were obtained using image data in real time. The results showed that by employing dual air jets at the front end of the chamber, the density of the fibre material was improved. We conclude that through multiphysics modelling, it was possible to identify the optimum air-jet configurations leading to fibre uniformity and its distribution. The work also paves the way for incorporating a vision system to evaluate fibre density in real time.

Keywords:
Non-woven steel fibre; steel fibre casting, melt and overflow; pneumatic conveying; multi-physics simulation