Fig 1. Daily production report shows hour-by-hour production trend and distribution chart for a selected day with minmax, average and variation statistics for comparison. Condition monitoring provides a view to vibrating crusher and screen components for predictive equipment maintenance.THERE IS a lot of measured real-time information available in every crushing plant. On-line information is obtained either from each Metso crusher’s machine automation system IC (Intelligent Controller) or separately installed additional sensors and belt scales.The only thing that remains to be done is to process and analyse all that data for showing the essence of it for efficient plant maintenance and profitable production.All the collected data is brought into a motor home using wireless communication based on WLAN technology. The motor home is a purpose-built environment inside an on-site container. In this environment selected variables can be monitored for assessing the plant performance. And to make all this even more flexible, the data can be transmitted to a crushing plant company office using GPRS/3G mobile data communication technologies. Hereby, all the last-minute reports are accessible to the crushing plant managerial staff anytime and, basically, anywhere within the reach of the cell phone network.

Production and fuel economics reports

Basically, monitoring and reporting can be customized to fit customer needs. However, there are certain off-theshelf reports to provide a lot of useful information for the plant supervision. The production report is one of these. Requiring at least one belt scale for measuring the total production, the production report shows production rate (tons per hour) for a selected reporting period e.g. a day or a week. In addition to graphic trends and distribution charts, the production report reveals deviation from the average production in terms of min-max values and standard deviations. Having installed and fired up, the production report constantly keeps track of the plant production storing all the data covering the life-cycle of the plant.Fuel consumption is always an interesting concern. The fuel consumption report gives fuel consumption of each crushing unit (liters per hour) and their total consumption (liters per hour) for a selected reporting period allowing tracking down fuel consumption changes over time. By comparing consumption trends and distribution charts, fuel economics assessment cannot be easier than this. And if there were belt scales available, the efficient fuel consumption could be even evaluated in terms of measuring consumed fuel per produced ton of aggregates (liters per ton).

Availability reports

Crushing plant availability can be assessed as well. The availability report calculates time periods for each crushing unit during which the unit is running. By storing the availability times between start-ups and shutdowns, the crushing plant operation time (hours per day/shift) can be recorded, analyzed and reported. More to this, the availability report can be taylored to evaluate efficient crushing hours during which the plant is really working and producing aggregates. Consequently, the ratio (0-100%) between efficient crushing time and total running time can be reported for any selected time period. This gives boost to efficient plant operations for a better productivity.

Reports on non-choke or inadequate feeding

Non-choke feeding to crushers is avoidable through smart plant-wide crushing plant controls. But in order to estimate severity of that in a systematic manner is not straight-forward without constant monitoring and reporting. The crusher choke feeding report makes use out of crusher cavity level sensors by analyzing their level measurements. By calculating average, min-max values and deviation from the average, it can be shown how often the single crusher suffers from non-choke feeding to it. This serves as a good starting point for improving plant-wide crushing plant controls.In some cases, the bottleneck of the crushing plant productivity is the material feeding to the process. In mobile plants, the feeding is human operated and, therefore, subject to variations in human operations. Occasionally, the size of the human-operated machine simply does not allow adequate feeding to the crushing plant. To hunt down time periods when the crushing plant suffers from inadequate feeding, there is a specific report for that. The report calculates the ratio between inadequate feeding over the total operation time telling if the feeding really is the soft spot.

Condition monitoring for crushers and screens

Machine-specific condition monitoring focuses on vibrating components in crushers and screens such as drive shaft bearings, safety plate wearing and gears. The low, middle and high frequencies of monitored components are measured and supervised in real-time to detect abnormalities due to slow or fast wear, looseness or imbalance. The condition monitoring enables efficient and predictive maintenance saving the crushing plant from component breaks and resulted maintenance costs and production losses.