Controlling Energy Hogs #3
Foundry Analysis (Dust Collection Systems)
Length of study: 1 month
Sensors used: AC Power Monitoring Sensors
Implementation time: 2 hours
Key data points included: Electric power used every 2 seconds, 24/7
Projected Annual Savings: Approx. $38,000/year
Capital investment required: One variable speed drive
Pricing: complete system is under $18,000 (AFS corporate members receive a discount of over 20%).
Projected ROI: Approx 6 months
A major reason that the dust collection system was used was the dust created by the shakeout system. When the shakeout system was not in operation, the dust collection system could usually be shut down soon after shakeout operations were completed. The host foundry wanted a better understanding of how their dust collection system was being utilized in concert with the shakeout system.
The research team developed 2 key project goals hoping to reveal savings opportunities with the relationship between shakeout table operations and the running of the dust collection system:
- Monitor the synchronization of a shakeout table and dedicated dust collector
- Identify opportunities for energy savings from improved synchronization
What We Looked At
For this project, we instrumented the power used by the shake-out table and correlated that with the power used by a dedicated dust collector. The dust collector was driven by a 250 hp motor and was used exclusively to minimize airborne dust generated by the monitored shakeout table operations.
The shakeout table was operated intermittently during weekdays and evenings but was not operated during the weekends. Daily workflow needs at the foundry determined the schedule for shakeout table operations and we found that these shakeout table operations were different every day during our monitoring period.
After collecting extensive data for the first two months, we selected a 2-day period to perform a detailed analysis of total energy usage and the time synchronization of the shakeout table with the dust collector. We used a 2 second measurement resolution for measuring power and for determining the precise time of day in which these two systems were operating or off.
- Measurements of 2 systems revealed significant lack of synchronization. During the 2 days of our detailed analysis:
- Shakeout table was operated 17.9 hours and turned on then off 77 times.
- Dust collector operated 40.4 hours and turned on then off 8 times.
- Dust collector was operated unnecessarily during 22.5 hours when there was no overlap.
- A short buffer period of additional dust collector operational time may be needed after the shake-out table was shutdown.
- Insights: There is synergy in synchronously monitoring different types of production equipment. Energy saving opportunities can be identified with a high-resolution (2 second interval), synchronous set of measurements; often different types of sensor measurements can be combined to discover important trends and opportunities for saving energy and production time.
Examples of Project Savings Recommendations
- Reducing excess operation time for dust collector during weekdays when shakeout table is not in operation will result in an estimated savings of $38,000 per year.
- Reduce excess operational time for dust collector during weekends and other non-operational periods.