Metso’s condition monitoring helps mill team to target and optimize maintenance of Indah Kiat’s new paper machine in Indonesia
The mill maintenance team at Indah Kiat’s Perawang mill has found the online system monitoring and its time trending capability helps them to isolate and target the real causes of machine vibration and avoid unnecessary and unscheduled repairs. This added intelligence about the actual mechanical condition allows them to prioritize and optimize labor and material planning to make them more time and cost efficient.
The Perawang mill is on the Indonesian island of Sumatra
The old English idiom “an ounce of prevention is worth a pound of cure” is being proven true and timeless by the 4-person predictive maintenance crew at the Perawang mill of Indah Kiat Pulp & Paper, an Asia Pulp & Paper (APP) subsidiary in Indonesia. Their efforts to start up paper production on the new PPM6 in early 2013 have been aided by a Metso Sensodec 6S online predictive maintenance system that has allowed them to pinpoint problems, make decisive time–effective and cost–efficient corrective actions and operate the machine in the best possible speed zone to minimize machine vibration. Indeed, an ounce of detection has saved them a pound of trouble. The 9.7 m width PPM6 produces uncoated woodfree copy paper. The target operating speed is 1500 m/min.
The decision to include an online predictive maintenance system was indeed carefully considered since the machine is a hybrid configuration, with newly designed and manufactured sections and some older sections that had been sitting in their original delivery crates for a number of years. What was the condition of the older components after so many years stored in a tropical environment? The results of the inspections were depressing; lots of corroded bearings were found, but changing all of them was not possible due to the high costs and long delivery time of replacement bearings. More intelligence was needed to tell them the actual running condition of the equipment and how it was changing over time.
To alleviate these risks to a smooth startup the mill ordered the Sensodec 6S system which continuously monitors the mechanical condition of major rotating components, gears and bearings. Time trending in the system allows the predictive maintenance team to detect problems early in their development stages and make the right corrective actions at the best time. This insight would augment their own maintenance skills.
Predictive maintenance is a knowledge-based discipline so user training on how to interpret vibration signals is a key ingredient in a successful implementation plan. In addition to providing the system tools, Metso conducted thorough on-site training for the maintenance team. Some were familiar with the product from their work at another Indonesian mill, while others were new to the technology.
Backbone for mechanical maintenance
Lassi Holm, Maintenance Manager, says “We are happy with Sensodec and indeed it has helped greatly to coordinate our maintenance resources, both manpower and material. On-line condition monitoring combined with our own experienced vibration analysts and support by specialists from Metso has give us the time to assess the situation and the actions needed. As a result, we have changed much fewer bearings then expected.”
Often finding out what is not the problem is just as valuable. For instance, he says that with the a system’s information they know when the cause of vibration is the critical speed of the machine and not the damaged bearing. Then, the machine speed can then be adjusted to minimize vibrations. They have learned to be patient and to follow the trends instead of making hasty repairs. Only once has a bearing failure (due to disconnected lubrication piping) caused unscheduled machine downtime. For these reasons Holm is a firm believer of on-line condition monitoring as a backbone for paper machine mechanical maintenance.By Mark Williamson, Journalist Engineer