Project development for the control of tail threading
In face of the identified scenario, we began to study the process and created a roadmap of actions and developments in drying, which would support the implementation of an advanced grammage control during the tail threading, which would be able to predict the final sheet grammage at the end of the dryer.
“We concluded that the time for process adjustments and production acceptance on the machines could be reduced with the application of artificial intelligence added to advanced process controls. In this way, the technology would be used to have the fastest production acceptance on the cutter, reducing process adjustment times for sheet quality parameters”, explains Heller Braga, Specialist in Automation and Process Optimization at ANDRITZ.
Suzano approved the idea and then the teamwork continued with the elaboration of a schedule of actions and scheduling of best moments to test the new technology. The first two tests generated adjustments. “The third opportunity came right after a machine shutdown. The Suzano and ANDRITZ teams, after analysis, identified that this would be a good time to test the project again and that's what we did”, says Heller Braga.
After the tests, the team analyzed four downtimes that were used as a reference, registered in November last year. With this, it was observed that the advanced control managed to reduce the passage time by approximately 40%. “At the Imperatriz Unit, the machines in the drying area are not designed to be a bottleneck for production. With the control, we were able to increase the machine's uptime and, consequently, the plant's operational stability”, says Production Consultant Lucas do Nascimento.
After the advanced controls, with the process being resumed more quickly, we reduced the machines' unproductive time. According to Edson Hélio, the results created a new milestone for the Imperatriz Unit. “We increased the availability of the machines, which allowed us to surpass previous monthly production records at the mill”, recalls the Executive Production Manager.