Online and manual (offline) vibration monitoring of equipment for reliability centered maintenance

Abstract

As the cement industry evolved, keeping equipment running without failure became crucial. Loss in production due to equipment failure was no longer affordable due to the increasing demand. In the cement industry, maintenance is a costly and at the same time controllable expense. The initial concept of equipment maintenance was reactive maintenance. Scheduled or preventive maintenance replaced reactive maintenance, resulting in better equipment availability. Even with scheduled preventive maintenance unprecedented failures occur. Now the focus in the industry is shifting from scheduled maintenance to the new technology of constantly observing machine condition and predicting the condition in advance. This is predictive maintenance. The source of equipment abnormality is identified and corrected which prevents the failure in the future. This is reliability based maintenance. More concentration is focused on providing advance warning of signs of trouble to prevent sudden failure. Predictive maintenance is the current trend in the manufacturing Industry. Condition monitoring through vibration monitoring and oil analysis is the latest technique of maintenance to achieve higher equipment availability. Holcim has evolved in last decade from preventive maintenance to reliability centered maintenance through condition monitoring. Condition based maintenance is the center of maintenance activity at the Holcim Portland Plant in Florence, Colorado. The plant has been in operation since May 2002. As part of the condition monitoring program, the plant has installed online vibration monitoring systems on all critical equipment. The online transducers are connected to the centralized control room through PLC's. The equipment has settings for alarm and shutdown in case of excessive vibration. Another vibration monitoring tool being utilized by the plant is an online surveillance system. This combines both continuous monitoring as well as Fast Fourier Transform analysis. The plant also has offline vibration monitoring routes where the data is collected manually by field technicians and then analyzed. This technical report presents information about the function of online and offline vibration monitoring. Brief information is presented about the current vibration monitoring system being used at the Plant. A case study is presented to show the cost justification analysis of implementing a vibration program. The report gives a brief comparison between online and offline monitoring showing the advantages and limitations of both. The investment required for the system installation as well as cost savings as a result of early prediction of equipment operation issues are presented.