Open Cut » Maintenance & Equipment
This study has led to the development of a computerised method whereby the efficacy of the ventilation system on draglines can be evaluated by determining whether there is adequate air movement throughout the machine house to remove the heat generated by the drives and MG sets. This approach has particular application to troubleshooting individual draglines with a specific over-heating issue or when evaluating a proposed ventilation arrangement for a new dragline. The viability of the method, which uses Computational Fluid Dynamics to model the airflow and temperatures around the machine house has been established by calibrating it against field test data obtained from site testing on two existing M8050 draglines. Following calibration of the models, the effects of making various conceptual changes to the way the air enters and leaves the machine house were investigated with the findings presented in this report.
Dust control issues were also considered in the study. A comparison of various filtration approaches as currently being used on draglines and elsewhere has been presented, along with observations by WBM and site personnel in respect of how these systems perform in practice. Many sites expect the dust filtration arrangement to be “self cleaning” in keeping with broad claims to that effect in promotional material from the suppliers of the filtration elements. In practice, most systems require routine cleaning and the few sites identified that expressed a high degree of satisfaction with the filtration system performance on their draglines were those that undertook routine cleaning of the filtration elements and maintenance of the scavenge system. The design of the layout of the filtration elements and the scavenge system is critical to maximizing the “self cleaning” potential of the entire filtration system and this area of endeavour is worthy of consideration as a separate investigation in the future.
Various cost estimates have been provided for different ventilation and filtration options to help calculate cost-benefit ratios by operators interested in modifying their draglines.
An e-newsletter has also been published for this project, highlighting its significance for the industry.