The Imperatriz Unit in Maranhão has adopted a solution that predicts faults in high criticality processes and reduces downtime for automatic on-off type valves.
The Suzano Group is one of the largest integrated pulp and paper manufacturers in Latin America, with five industrial units located in Brazil. One of these, the Imperatriz Unit, in Maranhão, is one of the company's most advanced facilities within the scope of Industry 4.0. The entire array of instruments and measurement devices that are highly critical and of high impact criticality is continuously monitored. Their new feature is the intelligent use of the automatic on-off valves, with access to advanced diagnostics and online features. The result is the failure anticipation within the plant, with focus on predictive maintenance.
"We use three types of valves: automatic control valves, automatic on-off valves and motorized valves. The first ones already have a certain intelligence and access to predictive maintenance. In the case of the motorized valves, the maintenance is preventive. Our work focused on the on-off ones, as conventional models have been replaced with advanced diagnostics-equipped devices", summarizes Leandro Yamamoto, Automation and Instrumentation consultant in Suzano's Maintenance Management department. The specialist has been coordinating the adoption of on-off valves with built-in intelligence since last year.
Advanced diagnostics has improved predictive maintenance
The goal of Yamamoto's work is to reduce downtime of the automatic on-off valves considered to be of high criticality, meaning that these can have an influence on the processes and costs of the plant. According to Yamamoto, this type of valve represents 8% of all the installed on-off devices at the Imperatriz facilities. Today, using advanced diagnostics, Yamamoto calculates that is possible to have a failure anticipation rate of 100% in the cooking and evaporation phases of pulp production.
So as to achieve the current level of excellence, Suzano's team used failure reports in automatic on-off valves as a baseline, and then focused on the high criticality group. The evaluation involved direct and indirect aspects, including information such as repair kit consumption and the reduction in service life of peripheral components. "We already have efficient maintenance in place, but we identified opportunities for improvement: mainly regarding the devices installed in corrosive environments and those which undergo greater vibrations within the plant", explained the specialist.
Critical on-off valves were prioritized in the process
The Neles Axiom Hart platform was chosen due to the technology's ability to process and send data, such as information regarding total cycles and pressure. "Depending on the pressure, we can check for problems in the filter elements and then maintenance can factor in devices which are peripheral to the automatic valves, thereby predicting failures", Yamamoto states. He highlights that the unit has even established a new maintenance plan, which is now more predictive in nature, for the filter elements.
With the adoption of intelligent automatic valves, Suzano is not limited to sensitive field inspections which are able to identify failures in more advanced stages. Nowadays, the unit is able to align maintenance downtime with normal interruptions, such as those required for boiler cleaning. In other words, having to wait for conventional maintenance downtime is not necessary, and this reduces the mobilization and labor costs involved, according to Yamamoto.
Open standard, interchangeability and robustness define Neles Axiom nonincendive on-off valve controller
For Anderson Lopes, Services coordinator at Neles, automatic on-off valves with advanced diagnostics are quite new to the pulp and paper industry, and Suzano is a pioneer in the adoption of this technology. "Traditional devices are unable to predict failures, and this fact increases the importance of the sensory inspections of technicians in the field, an external factor which depends on the professionals' experience", he notes.
Besides the predictability of failures, which improves the performance of predictive maintenance, Neles Axiom’s technology can be integrated into any industrial control system. With this, each device can be seen in the plant's control panel. "A single technician can oversee the process because he will have the status of the valves visible on-screen at his control room workstation", explains Lopes.
The third advantage is the equipment's cost/benefit relationship. Neles Axiom's solution features greater mechanical and electronic resistance, which is better suited for corrosive industrial environments with heavy vibrations. It's explosion-proof, which is why it is used for several oil and gas applications. "It's a device that offers a greater MTBF, in other words, a longer mean time between failures, when compared to traditional devices for the same investment", Lopes explains.
Even wider control with Neles SwitchGuard
The successful adoption of advanced diagnostics in the on-off valves also influenced the choice of another technology, the Neles SwitchGuard intelligent on/off controller, which also focuses on predictive maintenance. With this acquisition, Yamamoto estimates that 20% of the on-off valves considered to be of high criticality to Imperatriz should receive Neles' advanced diagnostics technology. "Because we work with statistical evaluations, this is a comfortable percentage for us regarding a reduction in the rate of possible failures", he concludes.
The text has been up-dated in July 2020, due to company name change to Neles.