Each Multilog IMx-S comes with either 32 or 16 dynamic analog signal inputs and eight digital channels. You can configure the inputs for a variety of sensors, including accelerometers and proximity probes, to measure acceleration, velocity, displacement, temperature and other parameters. You can use the digital channels for event-driven data collection, triggered, for instance, by speed, amps, a process variable or digital status (indicating an asset currently is operating in a specified range). You can attach several measurement points to one channel and take both AC and DC measurements on the same channel. You can establish individual conditions for warning and alarm for each point, with levels governed by machine speed or load.
Monitoring in Action
Here’s how Gulf Chemical has implemented the system:
The SKF IMx-S technology monitors multiple components in designated critical assets. For example, the system’s dual sensors (vibration and temperature) applied to an overhung fan keep watch on two motor bearings, two shaft bearings and one tachometer using eight analog channels and one digital channel. Data are wirelessly transmitted within a 100 ft. radius to a strategically located wireless network point in the plant.
Each sensor in the drive train has a predetermined warning and caution threshold. A simple visual “stop light” indicator (red for warning, yellow for caution and green for normal) appears on the system’s graphical interface on LCD screens in the reliability offices and the operations digital control center. When a threshold is exceeded, the indicator turns yellow or red; an overview screen pinpoints the source and allows a reliability technician to access a photo layout of the actual asset with stop light indicators showing temperature and overall inches-per-second parameters. This allows the person to quickly identify the questionable part of the rotating assembly.
The system enables all relevant parties to be brought up to speed in a timely manner regardless of their location. The supervisor and maintenance foreman for the area where the equipment is operating as well as the reliability and maintenance superintendents simultaneously receive e-mails.
After confirming via a handheld monitoring unit that online data are correct, the reliability department performs both a complete amplitude and phase analysis on the failure and creates a work order for maintenance that gives appropriate actions that need to be taken to address the problem. Once corrective work is complete, a reliability specialist takes data to check the adequacy of the repair and that the initial failure wasn’t masking other issues.
Total time elapsed from the initial warning to repair and verification depends upon the size of the equipment and severity of the problem but usually is less than 12 hours.
The @ptitude Observer software serves as the primary HMI (human/machine interface) for asset failure notification; its simplicity has made life easier for management and the workforce. The stop light indicators allow an operator without any experience in vibration monitoring to identify deviations from normal operating condition. The operator clicks on an auto analysis tab and reads the analysis report to learn what’s wrong, and then notifies maintenance staff for remedial action.
The system’s unique built-in hardware auto-diagnostics continuously check all sensors, cabling and electronics for any faults, signal interruption, electrical shorts or power failures. Any malfunctions will trigger an alarm; in the case of power failure, the system automatically restarts when the power returns.
For Gulf Chemical the system has fully supported condition-based maintenance objectives while providing measurable economies by reducing the time and staffing required to analyze a deviation from operating norms.
The SKF system has helped end the need for multiple employees to run routes, shortened the time required to analyze data, and minimized risks of potential equipment failures due to excessive time between notification and correction. In addition, mechanics in the field now can call on a radio or cell phone to receive accurate data about repairs within seconds without waiting.
Top management and reliability staffs at Gulf Chemical understood at the outset that a proactive approach toward maintenance in partnership with an experienced and innovative supplier could generate improved performance, reliability, economy and service life of critical assets. The Freeport facility’s experience has proven this and has cast Gulf Chemical and SKF as partners in progress.
Casey A. Connolly is continuous improvement manager for Gulf Chemical & Metallurgical Corp., Freeport, Texas. E-mail him at Casey.Connolly@eramet-gulf.com. Frank Mignano is senior account manager at SKF Reliability Systems, Houston. E-mail him at Frank.Mignano@skf.com.