Summary & Goals
Customer purchased a process line for copper reclamation from an Italian company whom specialized in Aluminum. After a few months of startup, the system they provided was barely able to run more than 2-3 hours at a time. With management losing patience, engineering called upon Logicon to provide control system design services to help rectify the situation. The goal for the customer was to have a line that was able to sustain week long production runs with minimal downtime due to control system inefficiencies.
Unfortunately our customer appeared to have been duped by the vendor. The system that was installed was basically an aluminum reclamation line on steroids. The aluminum lines that the vendor typically made produced ingots no larger than a standard envelop. The copper line however was purchased to produce 80 pound ingots approximately 3 feet long. The vendors figured the same process would work, they would just multiply the engineering by a factor “x” and all would be fine. This was not the case.
By the time Logicon was called in, the plant and vendor had already undergone several equipment replacements due to the inability of their “aluminum system” design to work with the copper system that was desired. What was left was the required control system modifications to the process to properly run with copper instead of aluminum. The vendor, having lost money on the project, was finished with their support and left their customer within the first couple weeks of our onsite presence.
We immediately tried to educate ourselves on the control system infrastructure, especially as this was a European designed system. Logicon had 3 team members onsite for a few weeks straight as the details started to come together. Working with the plant team, we took a process flow approach to solving the issues.
The first item in line of the process was the surge drum that received the flow of copper upstream from the oven and rotated on a PID loop to output a consistent flow to the forming wheel. The tuning of the PID loop was somewhat precarious as there was no ability to shut off the flow of copper from upstream. So the system had to output a specific flow of copper while monitoring an overflow situation of the drum from upstream.
Once the flow of copper was controlled existing the drum, the speed of the forming wheel had to be manipulated. A formed chamber ran beneath the vertical wheel with cooling jets. The copper is cooled enough to become a soft and pliable solid. That formed copper would them proceed vertically 25 feet in the air through guide rails to the gripper rollers and cutting area.
The grip roller speed was manipulated by the “bow” of the vertical copper and the amount of over or under feed was seen with photo eyes. The grip roller had to operate fast enough to keep the copper from overfeeding from the extrusion wheel but slow enough so it did not pull on the copper too tight and break the vertical extrusion. Once through the rollers a sensor measured the length and actuated a flying knife that would pinch cut the extrusion into an ingot of specified length. The cut ingot was then introduced to a water bath for additional cooling making the ingot hard enough to be picked by the robot and not bend.
The robot palletizer stacked a pattern of ingots in a cross pattern up to 7 levels high with an approximate weight of a single pallet at around 5000 lbs.
The scope expanded from control system troubleshooting to Logicon learning the process of melting copper and the methods used to manipulate it into a continuously extruded bar for on the fly cutting into ingots. Logicon worked side-by-side with plant engineers to blend the process status with the control system actions to determine the appropriate changes that needed to be made to smooth the process out to sustain production efficiently. Logicon provided over 1.5 years of support to the facility. The project was a resounding success and the plant was able to achieve their profitability goals on the line.