May 25, 2023

Overview
Grantek was contacted by a client in Pennsylvania, in the carbon fiber industry. The client has four furnaces that produce specialized carbon materials for various applications. However, the heavy instrumentation controlling temperature, pressure, and gas flows was operated through a series of old analog dials and pushbuttons. The process was extremely manual and relied heavily on operator knowledge. Some of the lead operators were getting close to retirement, prompting the client to look for an automated solution.

Challenges
The challenge was to develop an automated system that provided reliable and consistent controls for temperature, vacuum, and gas delivery that modeled the manual steps performed by the operators. The solution involved several iterations of documenting the process steps in close collaboration with the client’s engineers and senior operators, who had the most detailed knowledge of the process. Grantek provided a recipe system that allowed for modifications as needed per run, and a simulation of the furnaces running was presented to the client before deployment to ensure the process operated as expected. Commissioning was challenging as the process is a week-long, but key phases of the process were successfully tested, and the system was monitored during the run.

Due to the criticality of the process, the client also required that the new electrical wiring allowed for the existing manual controls to override the new automated controls via manual switches. This allowed for manual control as a backup in case of computer or programmable logic controllers (PLC) failure. The client needed to ensure that they could save runs as they are a week-long, and even a short anomaly during critical phases in the process can cause the run to be lost. There were electrical challenges to accomplish this, such as retrofitting the inductive furnaces for control and feedback and other old equipment to also allow manual overrides.

During the design phase additional features were added that ultimately improved efficiencies and reliability of the new automated system. Some software design enhancements included active sensor management such as being able to disable a redundant sensor that had failed. Additionally, error steps were created which immediately handle a critical alarm through a series of controlled and repeatable shutdown steps. Finally, the computerized system allowed the client to collect significantly more data on the process through automated trending and reports which helped the client make process decisions such as improving their heat up control strategy and duration now that the N/S bank on the Acetylene feed station was open. They were also given portable tablets that allowed them to always monitor the process during their work, whereas historically they needed to periodically go up to the control room to monitor dials.

Overall, the project involved a range of complex engineering challenges; however, Grantek’s expertise and collaboration with the client’s team led to a successful implementation of an automated system that allowed for better control, monitoring, data capture, and reporting.

Solutions
Based on the implemented automated system, the client experienced improved repeatability and reliability of their carbon fiber manufacturing process. The automated controls have eliminated the inconsistencies and delays associated with manual controls, leading to a more streamlined and efficient operation. Additionally, the recipe system developed by Grantek allows the client to modify their system as needed and preserve the process knowledge that might have been lost due to retiring operators. The preserved knowledge and improved repeatability of the system will lead to cost savings in the long term. The client is considering implementing similar solutions on other production lines and sites, which could lead to further cost savings and improvements across their whole enterprise. The new system provided the client with a more streamlined and efficient operation, allowing for better control, monitoring, and automated data capture and reporting. The client was thrilled with the results and is now better positioned for the future.