The following case study describes and explains a typical remote analysis application of continuous friction/lubrication monitoring on a mixer in chemical plant. The continuous surveillance was set up in a very effective way for the customer and analyst:
- For the Customer: Easy detection, fast diagnosis and monitoring from the friction issue on a critical mixer asset with low upfront investment and lower costs than manual/traditional online monitoring.
- For the analyst: Continuous data, instant trend data and 24/7 protection, higher confidence without any travel or measurement time spent.
Equipment, plant overview, Context
The Chemical site is a Phosphoric Acid Plant operating 24 Hours 7 days a week, established for many years in Africa. The Equipment in question is a large mixer involved in the acid production and a very large fan for production air treatment. Routine measurement performed with potable data collector indicated friction on both of these machines bearings. Cage frequency issues were detected, indicating higher than normal levels of friction. These raised levels would not warrant an immediate replacement but the next planned shutdown was in 10 months time. I-Care suggest the installation of Wi-care wireless vibration/temperature monitoring system and the analysis/trending by its remote team to ensure no premature escalation in the evolution of the defect.
The Wi-care system is set up on the main bearing housing of the mixer shaft.
Outlined below is the standard spectrum collected with the Wi-care wireless monitoring system at the lower radial position. Display is in acceleration units G PK. The dominant frequency appears at 185 Hz and its harmonics. In addition there is a lot of random vibration/noise visible in the spectrum indicating friction
Analyst diagnosis and spectrum justification: Friction in mixer bearings
Wi-care data from May 2014.
Seen below is a comparison of acceleration spectra made over a period of two measurements within 6 months. Measurement performed with CSI Data portable collector in April and October 2013
Portable analyzer data collection-April/October 2013
Same predominant frequency from October 2013 around 180 Hz (variable machine speed).
The friction is easy to identify with the portable data collector and the Wi-care wireless system even though the levels are not high. Close attention
to bearing lubrication levels based on Wi-care monitoring maintains a stable friction condition and the avoidance of a decrease in bearing health.
Following the diagnosis and remedial action, Wi-care provided a clear trending of data to the operators and predictive team.
Wi-care latest set of data and trend