Upgrade Evaluation, Port Hedland, WA, Australia
Two 6000 t/h Demag bucketwheel reclaimers had been in operation at BHP Iron Ore's Nelson Point port facility for over 20 years. A major expansion of the south yard facility prompted the need to increase the continuous capacity of the Demag machines towards 10 000 t/h and increase their life expectancy beyond the design life of 25 years.
Sinclair Knight Merz was commissioned to undertake an experimental and finite element analysis program to identify the current capacity and performance limits of the machines and, through Krupp, identify upgrade options to improve average and peak continuous rates.
To develop this information, a finite element model of the entire machine was constructed and exercised to identify the highly stressed areas during reclaiming operation. Strain gauges were mounted at these key locations. Data was recorded from these and approximately 20 other transducers including bucketwheel power draw, boom conveyor power, instantaneous reclaim rate, slew angle, etc. This raw data was the basis for identifying the performance limits of the machine and making rational decisions concerning upgrade options. Machine fatigue damage, remaining life and the effects of each upgrade option on future fatigue life was a major concern. Accordingly, Sinclair Knight Merz used the computer model to evaluate the fatigue damage impact of each option.
The performance limits of these machines were defined and significant insight was gained into the importance of various operating practices on machine life. Controls and capacity upgrade options were identified and costed.