Numerical investigation on the dedusting performance of rail grinding machinery

In mechanized rail grinding, excessive escape and deposition of grinding chips frequently cause mechanical failures, increase maintenance costs, and pose safety threats. This study leverages computational fluid dynamics and discrete phase model (CFD-DPM) to investigate the dedusting performance of rail grinding machinery. An experimentally verified two-phase flow model, comprising dedusting airflow and grinding chips, is developed. Notably, chip deposition on mechanical surfaces is innovatively characterized using a self-programmed criterion. Through in-depth analysis of airflow dynamics and chip migration, the dedusting mechanism is revealed for the first time, and the influences of operational parameters on dedusting performance are further evaluated. Results indicate that the dedusting mechanism lies in the size-dependent migration of chips under sluggish airflow predominating in the system. The airflow only entrains chips smaller than 100 μm, while coarser chips are governed by inertia. Consequently, only 6.45% of chips are collected, whereas escape and deposition are more pronounced, with respective ratios of 24.53% and 10.43%. Notably, as grinding angle decreases from +20° (field side) to -60° (gauge side), chip escape follows a rise-fall pattern, deposition drops markedly, while collection remains unchanged. Angles of +20° and -30° should be avoided. Moreover, higher suction volume mitigates chip escape, whereas both deposition and collection increase, with deposition rising more sharply. A volume of 13000 m³/h is recommended for chip collection and escape control, whereas 7000 m³/h is optimal for minimizing deposition. These findings offer valuable insights for enhancing the dedusting performance of rail grinding machinery.