Background
A brass foundry with seven electric-powered, inductive melt furnaces observed that its energy costs had risen far faster than their actual production, with its annual electric bill growing to over two million US dollars. Faced with further increases in energy rates, they embarked on a transformative journey to understand and improve their energy efficiency.
Challenge
The foundry’s induction furnaces were essential to their operations but were known for their energy-intensive nature. The lack of real-time insights into power usage for each individual furnace made it challenging to identify where the energy was being consumed or why overall energy use was outpacing actual production.
Solution
The first step involved installing a monitoring system to track the real-time power consumption of each induction furnace. The Sensor Synergy Energy Aware monitoring solution was selected for its low cost, ability to be self-installed, and the company’s reputation within the metal casting industry. A monitor was installed on each furnace, which captured current consumption every two seconds and stored the data in a secure cloud server. The Sensor Synergy Portal provided access to the data and visualizations by any authorized user via a web browser. For a detailed analysis, to supplement the high resolution power data, the staff provided production data for each furnace during each shift.
Findings and Results
With the Energy Aware real-time data at their fingertips, the foundry identified three opportunities for savings by simply optimizing processes and re-training staff. These steps provided $214,000 in annual energy savings without any further capital investment.
- Optimize non-production period power settings.
Differences in power usage for identical furnaces during non-production periods varied as much as 30% . Identifying the best practices and using those set-points consistently throughout the plant accounted for $20,000 per year in energy savings. - Re-distribution of furnace workloads.
In the review of electrical consumption per ton of production it was identified that three of the furnaces were typically operated at a much smaller loading factor. This was so low that the production of all three furnaces could be handled by a single unit. Units two and three were taken offline and reserved for peak demand periods. This resulted in a direct energy savings of $94,000 per year, with anticipated further savings on maintenance and operational costs. - Optimize production period power settings.
The detailed power data revealed that there was a variation in Energy Intensity (pounds produced per kilowatt-hour) of 31% resulting from variations in human-factor processes. By identifying the best practices, retraining the staff, and then monitoring results, an additional $99,000 in annualized energy savings was achieved.
Conclusion
Through a combination of Industrial Internet of Things (IIoT) technology, data-driven insights, and a focus on human-centric processes, the foundry not only slashed its electricity costs but also enhanced its overall operational efficiency. This case exemplifies how much opportunity there is for cost and efficiency improvements in energy-intensive industrial processes where there is a high potential for “human factor” process variation. In this case, the payback period for the investment in the Energy Aware monitoring solution was less than three weeks.